Add Installation, Contributing and Developing sections to the readme

Resolves #34

Author: mzur

README.md

@@ -1,5 +1,3 @@
-[<img src="https://raw.githubusercontent.com/andyholmes/gnome-shell-extensions-badge/master/get-it-on-ego.svg?sanitize=true" height="100" align="right">](https://extensions.gnome.org/extension/1485/workspace-matrix/)
-
 # Workspace Matrix
 
 GNOME shell extension to arrange workspaces in a two dimensional grid with workspace thumbnails.
@@ -18,3 +16,27 @@ This is a clone of the [Workspace Grid](https://github.com/zakkak/workspace-grid
 - Configurable timeout of the workspace switcher popup.
 - Two wraparound modes for navigating workspaces (optional).
 - Workspace labels in the workspace switcher popup (optional).
+
+## Installation
+
+[<img src="https://raw.githubusercontent.com/andyholmes/gnome-shell-extensions-badge/master/get-it-on-ego.svg?sanitize=true" height="100">](https://extensions.gnome.org/extension/1485/workspace-matrix/)
+
+The easiest way to install this extension is via the [GNOME Extensions](https://extensions.gnome.org/extension/1485/workspace-matrix/) website.
+
+## Contributing
+
+Pull requests for issues that are marked as "bug" or "help wanted" are always welcome. If you want to implement any other new feature, please open an issue about this first. See the next section on how to get started with development.
+
+## Developing
+
+You can develop this extension "live" while it is installed in GNOME on your system:
+
+1. Uninstall this extension if it is already installed. You can do this via the [GNOME Extensions](https://extensions.gnome.org/extension/1485/workspace-matrix/) website.
+2. Clone this repository somewhere, e.g. to `~/code/gnome-shell-workspace-matrix`.
+3. Create a symlink from this repository to the GNOME extensions directory, e.g.:
+   ```
+   ln -s ~/code/gnome-shell-workspace-matrix/wsmatrix@martin.zurowietz.de ~/.local/share/gnome-shell/extensions/gnome-shell-workspace-matrix/wsmatrix@martin.zurowietz.de
+   ```
+4. Restart GNOME by pressing Alt+F2 and running the command `r`. Do this whenever you want to apply and test a change of the code.
+
+If you change something in the gschema XML file, run `make` to recompile it. The `make` command also builds the ZIP file that can be used for new releases of this extension.