README: move installation instructions to INSTALLATION.md

Closes #59.

INSTALLATION.md

@@ -0,0 +1,34 @@
+# Installation
+
+#### The normal way
+
+    $ pip3 install neovim-remote
+
+On most systems this will be good enough.
+
+If you get a "permission denied" error, don't use `sudo` to force it! Use
+this instead:
+
+    $ pip3 install --user neovim-remote
+
+..and make sure that `~/.local/bin` is in $PATH.
+
+#### From repo
+
+If you want to test your own changes, it makes sense to put your local repo into
+_develop mode_. That way your Python environment will use the repo directly and
+you don't have to reinstall the package after each change:
+
+    $ git clone https://github.com/mhinz/neovim-remote
+    $ cd neovim-remote
+    $ pip3 install -e .
+
+Now, `pip3 list` will show the path to the local repo after the package version.
+
+#### From zip
+
+Download the [zipped
+sources](https://github.com/mhinz/neovim-remote/archive/master.zip) and install
+install them with either `pip3 install master.zip` or by running `python3
+setup.py install` in the unzipped directory.
+

README.md

@@ -58,16 +58,7 @@ create a new nvim process. In a terminal buffer, nvr will open a new buffer.
 
 ## Installation
 
-    $ pip3 install neovim-remote
-
-On most systems this will be good enough.
-
-If you get a "permission denied" error, don't use `sudo` to force it! Use
-this instead:
-
-    $ pip3 install --user neovim-remote
-
-..and make sure that `~/.local/bin` is in $PATH.
+See [INSTALLATION.md](INSTALLATION.md)
 
 ## Usage