Inline ISSUE_TEMPLATE links

When opening an issue using the ISSUE_TEMPLATE, most users would
remove the template's URL declarations from the bottom of the file.

Most of the URLs are short, so inlining them into the template itself seems to be a good enough solution.

.github/ISSUE_TEMPLATE.md

@@ -1,19 +1,19 @@
 **Which operating system and version is the project developed on?**
 
-**Which version of [`ruby`][ruby] is the project developed on?**
+**Which version of [`ruby`](https://www.ruby-lang.org/) is the project developed on?**
 
-**Which version of [`npm`][npm] is the project developed on?**
+**Which version of [`npm`](https://www.npmjs.com/) is the project developed on?**
 
-**Which version of [`ember-cli`][ember-cli] is the project developed on?**
+**Which version of [`ember-cli`](http://ember-cli.com/) is the project developed on?**
 
-**What is the [`rails`][rails] version?**
+**What is the [`rails`](https://github.com/rails/rails) version?**
 
-**What is the [`ember-cli-rails`][gem] version (from `Gemfile`)?**
+**What is the [`ember-cli-rails`](https://github.com/thoughtbot/ember-cli-rails) version (from `Gemfile`)?**
 
-**What is the [`ember-cli-rails-addon`][addon] version (from `package.json`)?**
+**What is the [`ember-cli-rails-addon`](https://github.com/rondale-sc/ember-cli-rails-addon/) version (from `package.json`)?**
 
-**Is your application server [multi-threaded][] (such as `puma` and `unicorn`) or is
-it multi-process (such as thin and webrick)?**
+**Is your application server [multi-threaded](https://github.com/thoughtbot/ember-cli-rails/commit/ef0a49546a8c2e5fb0a298ba455fba97289065a1) 
+(such as `puma` and `unicorn`) or is it multi-process (such as thin and webrick)?**
 
 **What are the contents of `config/initializers/ember.rb`?**
 
@@ -22,12 +22,3 @@ it multi-process (such as thin and webrick)?**
 **How are the EmberCLI-related routes defined?**
 
 **How is the application deployed?**
-
-[ruby]: https://www.ruby-lang.org/
-[node]: https://nodejs.org/en/
-[npm]: https://www.npmjs.com/
-[ember-cli]: http://ember-cli.com/
-[rails]: https://github.com/rails/rails
-[gem]: https://github.com/thoughtbot/ember-cli-rails
-[addon]: https://github.com/rondale-sc/ember-cli-rails-addon/
-[multi-threaded]: https://github.com/thoughtbot/ember-cli-rails/commit/ef0a49546a8c2e5fb0a298ba455fba97289065a1