Added Contributing file for v4

CONTRIBUTING-v4.md

@@ -0,0 +1,163 @@
+## Design Goals - Simplicity
+
+- Easy to use
+- Easy to develop
+
+**Easy to use**
+
+- Don't mimick API spec. Ansible spec should be a simplified version of API spec.
+- Goal is to expose *minimum attributes* to create, update or delete the entity.
+- Keep backward & forward compatibility in mind when creating ansible spec.
+
+**Easy to develop**
+
+- Three things need to develop a module:
+
+    a. [Module spec](https://github.com/nutanix/nutanix.ansible/blob/main/plugins/modules/ntnx_subnets_v2.py#L606) inside `get_module_spec()`, spec for running the API via sdk.
+
+    Example:
+    ```
+    def get_module_spec():
+        dhcp_spec = dict(...)
+        metadata_spec = dict(...)
+
+        module_args = dict(
+            ext_id=dict(type="str"),
+            name=dict(type="str"),
+            description=dict(type="str"),
+            subnet_type=dict(type="str", choices=["OVERLAY", "VLAN"]),
+            network_id=dict(type="int"),
+            dhcp_options=dict(type="dict", options=dhcp_spec, obj=net_sdk.DhcpOptions),
+            metadata=dict(type="dict", options=metadata_spec, obj=net_sdk.Metadata),
+        )
+        return module_args
+    ```
+
+    b. [Bootstrap code](https://github.com/nutanix/nutanix.ansible/blob/main/plugins/modules/ntnx_subnets_v2.py#L705) for creating and deleting entity.
+    Use v4 sdks which are available on [v4-documentation](https://developers.nutanix.com/api-reference?namespace=networking&version=v4.0) in creation, updation or deletion.
+
+    c. [Ansible module](https://github.com/nutanix/nutanix.ansible/blob/main/plugins/modules/ntnx_subnets_v2.py) plugin with [`run_module()`](https://github.com/nutanix/nutanix.ansible/blob/main/plugins/modules/ntnx_subnets_v2.py#L832) implementation.
+
+    Example:
+    ```
+    def run_module():
+    module = BaseModule(
+        argument_spec=get_module_spec(),
+        supports_check_mode=True,
+        required_if=[
+            ("state", "present", ("name", "ext_id"), True),
+            (
+                "state",
+                "present",
+                ("ext_id", "cluster_reference", "vpc_reference"),
+                True,
+            ),
+            ("state", "absent", ("ext_id",)),
+        ],
+    )
+    if SDK_IMP_ERROR:
+        module.fail_json(
+            msg=missing_required_lib("ntnx_networking_py_client"),
+            exception=SDK_IMP_ERROR,
+        )
+
+    remove_param_with_none_value(module.params)
+    result = {
+        "changed": False,
+        "error": None,
+        "response": None,
+        "ext_id": None,
+    }
+    state = module.params["state"]
+    if state == "present":
+        if module.params.get("ext_id"):
+            update_subnet(module, result)
+        else:
+            create_subnet(module, result)
+    else:
+        delete_subnet(module, result)
+    module.exit_json(**result)
+    ```
+
+## Spec generator
+
+The `generate_spec` method is designed to populate a specification object (`obj`) based on input attributes (`attr`) and additional keyword arguments (`kwargs`). Here's a brief breakdown of how it works:
+
+1. **Type Check**: Ensures the obj is a valid object.
+
+2. **Module Arguments**: Retrieves module arguments from kwargs or uses a default set.
+
+3. **Attributes**: If attr is not provided, it defaults to a deep copy of self.module.params.
+
+4. **Attribute Processing**: Iterates over each key in module_args and processes it based on its type:
+    - **Dynamic Objects**: Handles attributes with dynamic objects.
+    
+    - **Dict Type**: Recursively creates spec objects for dictionary-type attributes.
+
+    - **List Type**: Recursively creates a list of spec objects for list-type attributes.
+
+    - **Other Types**: Directly assigns the attribute value to the spec object.
+
+**Usage:**
+
+To use the `generate_spec` method, follow these steps:
+
+1. **Create a Spec Object**: Define the spec object that needs to be populated.
+
+2. **Define Attributes**: Prepare the attributes dictionary that contains the values to be assigned to the spec object.
+
+3. **Call the Method**: Invoke the `generate_spec` method with the spec object and attributes.
+
+**Example**
+
+Here's an example of how to use the `generate_spec` method:
+
+For Create Opearation:
+```
+sg = SpecGenerator(module)
+default_spec = net_sdk.Subnet()  // Root Node
+spec, err = sg.generate_spec(obj=default_spec)
+```
+For Update Operation:
+```
+current_spec = get_subnet(module, subnets, ext_id=ext_id) // Fetch the current spec
+sg = SpecGenerator(module)
+update_spec, err = sg.generate_spec(obj=deepcopy(current_spec))
+```
+
+## Workflow
+
+1. Create a github issue with following details
+ * **Title** should contain <font color="red">one of</font> the follwoing
+    - [Feat] Develop ansible module for \<api_name>
+    - [Imprv] Modify ansible module to support \<new_functionality>
+    - [Bug] Fix \<summary of issue> bug in \<ansible_module_name>
+ * **Labels** should contain <font color="red">one of</font> the following
+    - **feature**
+    - **enhancement**
+    - **bug**
+    - **test**
+
+ * **Project** should be selected
+ * **Assignees** - assign yourself
+ * **Task list** for list of tasks that needs to be developed as part of the fix
+    - unit tests
+    - integration tests
+    - sanity tests
+    - documentation
+
+2. Create <font color="red">one of</font> the following git branch from <font color="red">`main`</font> branch. Use `issue#<id>` from 1).
+ * `feat/<module_name>_issue#<id>`
+ * `imprv/issue#<id>`
+ * `bug/issue#<id>`
+
+3. Develop `sanity`, `unit` and `integrtaion` tests.
+
+4. Create a [pull request](https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/proposing-changes-to-your-work-with-pull-requests/creating-a-pull-request)
+
+5. Ensure <font color="royalblue">85% code coverage</font> on the pull request. Pull request with less than 85% coverage will be <font color="red">rejected</font>.
+
+6. Link the pull request in `issue#<id>`
+
+7. After the pull request is merged, close the `issue#<id>`
+