Rails installation using importmaps (#63)

* Update installation-importmaps.html.erb

Initial sections of setup guide

* Update installation-importmaps.html.erb

* Update installation-importmaps.html.erb

* Update installation-importmaps.html.erb

Added reference to Rails Guides working with Javascript article.

app/content/pages/frameworks/rails/setup/installation-importmaps.html.erb

@@ -8,3 +8,89 @@ framework: rails
 
   <%= render Page::ContributeComponent.new(file: current_page.asset.path.path) %>
 <% end %>
+
+In Rails 7+, Hotwire is configured by default using import maps. This guide will walk you through the files, gems, and configurations essential for this setup, ensuring a smooth integration right out of the box. Further information on Import maps can also be found on [Rails Guides, Working with Javascript in Rails](https://guides.rubyonrails.org/working_with_javascript_in_rails.html).
+
+## Setup
+
+## 1. Creating a New Rails Project:
+
+Begin by running the `rails new` command to generate a fresh Rails project. Once installed, delve into the Gemfile. This file includes several gems crucial for bundling the necessary dependencies for an import maps and Hotwire configuration. They include:
+
+ ```rb
+ # Use JavaScript with ESM import maps
+ # [https://github.com/rails/importmap-rails]
+ gem "importmap-rails"
+
+ # Hotwire's SPA-like page accelerator
+ # [https://turbo.hotwired.dev]
+ gem "turbo-rails"
+
+ # Hotwire's modest JavaScript framework
+ # [https://stimulus.hotwired.dev]
+ gem "stimulus-rails"
+ ```
+
+ After executing `bundle install`, run `rails importmap:install` to integrate the required configurations and files into your project.
+
+ ```sh
+$ rails importmap:install
+      apply  /path_to/gems/importmap-rails-1.2.3/lib/install/install.rb
+  Add Importmap include tags in application layout
+      insert    app/views/layouts/application.html.erb
+  Create application.js module as entrypoint
+      create    app/javascript/application.js
+  Use vendor/javascript for downloaded pins
+      create    vendor/javascript
+      create    vendor/javascript/.keep
+  Ensure JavaScript files are in the Sprocket manifest
+      append    app/assets/config/manifest.js
+  Configure importmap paths in config/importmap.rb
+      create    config/importmap.rb
+  Copying binstub
+      create    bin/importmap
+         run  bundle install
+ ```
+
+## 2. `javascript_importmap_tags`
+
+The installation command will automatically modify your `application.html.erb` file by adding the `<%= javascript_importmap_tags %>` ERB tag. The `<script>` tags inserted in your page header will correspond to the configurations in `config/importmap.rb`.
+
+## 3. Pinning Imports
+
+Think of your import map in Rails as analogous to a `package.json` file in an NPM package. It's where you declare (or "pin") your app's local and remote JS module dependencies. Use `config/importmap.rb` for this purpose.
+
+Pins can be added manually or with the `bin/importmap pin DEP_NAME` command. For instance, to pin the `lodash` library:
+
+```sh
+$ bin/importmap pin lodash
+Pinning "lodash" to https://ga.jspm.io/npm:lodash@4.17.21/lodash.js
+```
+
+This command updates `config/importmap.rb`:
+
+```rb
+pin "lodash", to: "https://ga.jspm.io/npm:lodash@4.17.21/lodash.js"
+```
+
+To remove a pin, either delete its entry in `config/importmap.rb` or use `bin/importmap unpin DEP_NAME`. Remember to restart your development server after any changes.
+
+## 4. Importing Pins
+Post-pinning, you can import a module into `app/javascript/application.js` or other scripts:
+
+```js
+import _ from 'lodash';
+```
+
+## 5. Importing Turbo
+Finally, import Turbo into your `app/javascript/application.js`:
+
+```js
+import "@hotwired/turbo-rails"
+```
+
+This makes the Turbo instance globally accessible via `window.Turbo`.
+
+## Conclusion
+
+This guide provides a basic overview of setting up import maps in Rails 7. Each component discussed offers its own set of configurable options, allowing you to tailor the setup to your application's specific needs.