Provide a fill_template script (#77)

Hi.

I think this template project is a wonderful idea to play around with
egui for ealuationa nd eventually starting something real with it.

But I found it kind of cumbersome to fill in the template consistently
over all the files, so I wrote this little script I would like to share,
in case it is deemed useful.

README.md

@@ -13,7 +13,7 @@ You can compile your app natively or for the web, and share it using Github Page
 
 Start by clicking "Use this template" at https://github.com/emilk/eframe_template/ or follow [these instructions](https://docs.github.com/en/free-pro-team@latest/github/creating-cloning-and-archiving-repositories/creating-a-repository-from-a-template).
 
-Change the name of the crate: Chose a good name for your project, and change the name to it in:
+Change the name of the crate: Choose a good name for your project, and change the name to it in:
 * `Cargo.toml`
     * Change the `package.name` from `eframe_template` to `your_crate`.
     * Change the `package.authors`
@@ -25,6 +25,9 @@ Change the name of the crate: Chose a good name for your project, and change the
   * Change the `'./eframe_template.js'` to `./your_crate.js` (in `filesToCache` array)
   * Change the `'./eframe_template_bg.wasm'` to `./your_crate_bg.wasm` (in `filesToCache` array)
 
+Alternatively, you can run `fill_template.sh` which will ask for the needed names and email and perform the above patches for you. This is particulary useful if you clone this repository outside GitHub and hence cannot make use of its
+templating function.
+
 ### Learning about egui
 
 `src/app.rs` contains a simple example app. This is just to give some inspiration - most of it can be removed if you like.

fill_template.sh

@@ -0,0 +1,27 @@
+#!/usr/bin/env sh
+
+set -e
+
+echo "To fill the template tell me your egui project crate name: "
+
+read crate
+
+echo "To fill the template tell me your name (for author in Cargo.toml): "
+
+read name
+
+echo "To fill the template tell me your e-mail address (also for Cargo.toml): "
+
+read email
+
+echo "Patching files..."
+
+sed -i "s/eframe_template/$crate/g" Cargo.toml
+sed -i "s/eframe_template/$crate/g" src/main.rs
+sed -i "s/eframe template/$crate/g" index.html
+sed -i "s/eframe_template/$crate/g" assets/sw.js
+sed -i "s/Emil Ernerfeldt/$name/g" Cargo.toml
+sed -i "s/[email protected]/$email/g" Cargo.toml
+
+echo "Done."
+