chore: update contributing doc, add to issue template, add section on…

… DCO (#256)

* chore: update contributing doc, add to issue template, add section on DCO

* chore: add instructions for downloading engine

.github/ISSUE_TEMPLATE/new_language.yml

@@ -65,6 +65,10 @@ body:
   - type: markdown
     attributes:
       value: |
+        ## Contributing
+
+        Check out our [Contributing Guide](https://github.com/flipt-io/flipt-client-sdks/blob/main/CONTRIBUTING.md) to learn more about how you can help contribute / implement this SDK request.
+
         ## Join the Flipt Community
 
         - [Join our Discord](https://flipt.io/discord) `#sdk-dev` channel to discuss your language request with the Flipt community.

CONTRIBUTING.md

@@ -48,38 +48,97 @@ The client shape should be as follows:
 
    1. `url`: The URL of the Flipt server to connect to.
    2. `update_interval`: The interval in seconds to wait for updated flag state.
-   3. `auth_token`: The auth token to use when connecting to the Flipt server.
+   3. `authentication_strategy`: The authentication strategy to use. Should be one of the following:
+      - `client_token`: Client Token Bearer key authentication.
+      - `jwt`: JWT Bearer key authentication.
 
    Note: If no namespace is specified, the client should default to the `default` namespace.
 
-2. **Evaluate_Variant** method: Should take in a flag key, entity ID, and context. Should return a variant result. Follow language conventions for naming.
-3. **Evaluate_Boolean** method: Should take in a flag key, entity ID, and context. Should return a boolean result. Follow language conventions for naming.
-4. **Close** method (language dependent): Should close the engine and free any memory allocated by the engine. Follow language conventions for naming.
+2. **Evaluate Variant** method: Should take in a flag key, entity ID, and context. Should return a variant result. Follow language conventions for naming.
+3. **Evaluate Boolean** method: Should take in a flag key, entity ID, and context. Should return a boolean result. Follow language conventions for naming.
+4. **Evaluate Batch** method: Should take in a list of flag keys, entity ID, and context. Should return a list of evaluation results. Follow language conventions for naming.
+5. **List Flags** method: Should return a list of all flags in the namespace. Follow language conventions for naming.
+6. **Close** method (language dependent): Should close the engine and free any memory allocated by the engine. Follow language conventions for naming.
 
-### 3. Setup Tests
+### 3. Interface with the Engine
+
+The client should interface with the engine to evaluate flags. The engine is responsible for connecting to the Flipt server, fetching flag state, and evaluating flags.
+
+You don't have to build the engine from scratch in order to develop a new client. You can download the latest engine version from the [releases page](https://github.com/flipt-io/flipt-client-sdks/latest) for your platform and use it while developing the client.
+
+### 4. Setup Tests (optional)
+
+If you like to add tests using Dagger, you can follow the steps below. If you are not familiar with Dagger, you can skip this step and simply provide instructions for running the tests locally.
 
 Feel free to ask the team for help with this step.
 
 1. Update the `test/main.go` file to include the new client in the list of clients to test.
 2. Update `test/main.go` to run the tests for the new client using Dagger. See the existing clients for examples.
 3. Ensure the tests pass locally by running `dagger run go run ./test/... --languages={language}` from the root of the repository. Note: You will need to have Docker, Go, and Dagger installed locally to run the tests.
 
-### 4. Update README
+### 5. Update README
 
 Update the [README.md](./README.md) to include the new client in the list of clients. Follow the existing clients for examples.
 
-### 5. Create a PR
+### 6. Setup Dependabot (optional)
+
+Add a new section to the [dependabot.yml](./.github/dependabot.yml) file for the new language if applicable. Follow the existing languages for examples.
+
+### 7. Create a PR
 
 Create a PR with the changes and we will review it as soon as possible. Please add any language specific idioms when it comes to packaging the client. This will allow us to automate and publish the client to the appropriate package manager.
 
 ### Conventional Commits
 
 We use [Conventional Commits](https://www.conventionalcommits.org/en/v1.0.0/) for commit messages. Please adhere to this specification when contributing.
 
-## Legal
-
-By submitting a Pull Request, you disavow any rights or claims to any changes submitted to this project and assign the copyright of those changes to Flipt Software Inc.
-
-If you cannot or do not want to reassign those rights (your employment contract for your employer may not allow this), you should not submit a PR. Open an issue and someone else can do the work.
-
-This is a legal way of saying "If you submit a PR to us, that code becomes ours". 99.9% of the time that's what you intend anyways; we hope it doesn't scare you away from contributing.
+## Developer Certificate of Origin
+
+We respect the intellectual property rights of others and we want to make sure
+all incoming contributions are correctly attributed and licensed. A Developer
+Certificate of Origin (DCO) is a lightweight mechanism to do that. The DCO is
+a declaration attached to every commit. In the commit message of the contribution,
+the developer simply adds a `Signed-off-by` statement and thereby agrees to the DCO,
+which you can find below or at [DeveloperCertificate.org](http://developercertificate.org/).
+
+```text
+Developer's Certificate of Origin 1.1
+
+By making a contribution to this project, I certify that:
+
+(a) The contribution was created in whole or in part by me and I
+    have the right to submit it under the open source license
+    indicated in the file; or
+
+(b) The contribution is based upon previous work that, to the
+    best of my knowledge, is covered under an appropriate open
+    source license and I have the right under that license to
+    submit that work with modifications, whether created in whole
+    or in part by me, under the same open source license (unless
+    I am permitted to submit under a different license), as
+    Indicated in the file; or
+
+(c) The contribution was provided directly to me by some other
+    person who certified (a), (b) or (c) and I have not modified
+    it.
+
+(d) I understand and agree that this project and the contribution
+    are public and that a record of the contribution (including
+    all personal information I submit with it, including my
+    sign-off) is maintained indefinitely and may be redistributed
+    consistent with this project or the open source license(s)
+    involved.
+```
+
+We require that every contribution to Flipt to be signed with a DCO. We require the
+usage of known identity (such as a real or preferred name). We do not accept anonymous
+contributors nor those utilizing pseudonyms. A DCO signed commit will contain a line like:
+
+```text
+Signed-off-by: Jane Smith <[email protected]>
+```
+
+You may type this line on your own when writing your commit messages. However, if your
+user.name and user.email are set in your git configs, you can use `git commit` with `-s`
+or `--signoff` to add the `Signed-off-by` line to the end of the commit message. We also
+require revert commits to include a DCO.