Cleanup installation instructions

Don't recommend yaourt when there are several better alternatives. In
any case, no AUR helper is supported by the Arch Linux team and if one
is installed the user should already know how to use it, i.e. not the
responsibility of gydl docs.

An alternative to this change, would be mentioning that gydl can be
installed, using an AUR helper and linking to this wiki page:

- https://wiki.archlinux.org/index.php/AUR_helpers

Also ran a spell checker and made some grammar improvments, as well as
ensuring there was a consistent line break at 80 characters.

README.md

@@ -1,7 +1,10 @@
 # About
-Gydl (Graphical Youtube-dl) is a GUI wrapper around the already existing youtube-dl program.
 
-It's developed to be a dialog'ish GUI for quick and easy video or audio downloads without disturbances.
+Gydl (Graphical Youtube-dl) is a GUI wrapper around the already existing
+youtube-dl program.
+
+It's developed with a dialog driven experience in mind. This provides a quick
+and easy video or audio downloads without disturbances.
 
 Big **thank you** to the developer(s) of youtube-dl! Check out their project:
 
@@ -13,7 +16,14 @@ Gydl is currently receiving a new design along with a rewrite to C. It will keep
 
 Thanks for your patience.
 
-# Installation and dependencies
+# Installation
+
+## GNU/Linux Packages
+
+* [Arch Linux](https://aur.archlinux.org/packages/gydl-git/)
+  (Credit: [AffeAli](https://github.com/AffeAli))
+
+## Source
 
 Gydl is written in Python3 and uses the GTK+3 toolkit.
 
@@ -24,24 +34,18 @@ To run it you need to have installed:
 * pygobject
 * youtube-dl
 
-**Archlinux:**
-
-[AffeAli](https://github.com/AffeAli) has created an [AUR Package](https://aur.archlinux.org/packages/gydl-git/) for Gydl, so you can install it by:
-
-    $ yaourt -S gydl-git
-
-Big thanks to him.
-
 # Usage
 
-When using Gydl, you have the option to download your Youtube Video as a **Video** or **Audio**.
+When using Gydl, you have the option to download your Youtube Video as a
+**Video** or **Audio**.
 
-Each of these options have a text entry, as well as 2 comboboxes managing quality and the format.
+Each of these options have a text entry, as well as 2 combo-boxes managing
+quality and the format.
 
 
 ![alt tag](http://i.imgur.com/o4pYQrX.png)
 
-When clicking on **Download** there are 3 scenarious you can face:
+When clicking on **Download** there are 3 scenarios you can face:
 
 * Download Finished - When your download has finished successfully.
 
@@ -55,9 +59,9 @@ When clicking on **Download** there are 3 scenarious you can face:
 
 ![alt tag](http://i.imgur.com/Vrys4YO.png)
 
-These dialogs will be presented to you as a little dialog'ish windows.
+These dialogues will be presented to you as a little windows.
 
-Notice that not every video/format can be downloaded in a specific format.
+Notice that not every combination of settings will work.
 
 Thanks for any involvement in this project, I hope you like it.