Add debian installation instructions.

Author: arusahni

README.md

@@ -32,9 +32,19 @@ That's exactly what `git-req` does.
 Installation
 ------------
 
-1. [Download the binary for your operating system from the release page](https://github.com/arusahni/git-req/releases/latest).
-2. Decompress the archive.
-3. Place the `git-req` executable somewhere in your `$PATH`.
+1. Install it:
+    * Homebrew (MacOS)
+        1. `brew tap install arusahni/git-req`
+        2. `brew install git-req`
+    * AUR (Arch Linux)
+        1. `yay -Sy git-req`
+    * DEB (Debian / Ubuntu Linux)
+        1. [Download the `*.deb` file from the release page](https://github.com/arusahni/git-req/releases/latest).
+        2. `dpkg -i /path/to/file.deb`
+    * Everyone else
+        1. [Download the binary for your operating system from the release page](https://github.com/arusahni/git-req/releases/latest)
+        2. Decompress the archive
+        3. Place the `git-req` executable somewhere in your `$PATH`
 
 The first time you run `git req <#>` it will prompt you for API credentials;
 use a Personal Access Token.

docs/index.html

@@ -71,6 +71,12 @@ <h2 class="subtitle is-uppercase">Getting started</h2>
                                 <li><code>yay -Sy git-req</code></li>
                             </ol>
                         </li>
+                        <li>Ubuntu/Debian package
+                            <ol>
+                                <li><a href="https://github.com/arusahni/git-req/releases/latest">Download the latest <code>*.deb</code> file from the release page.</a></li>
+                                <li><code>dpkg -i /path/to/file.deb</code></li>
+                            </ol>
+                        </li>
                         <li>Everyone else...
                             <ol>
                                 <li><a href="https://github.com/arusahni/git-req/releases/latest">Download the binary for your operating system from the release page.</a> At this time, only Linux and macOS are officially supported. Builds for other platforms are available, but untested.</li>