document workflow for local plugin development

Fixes #316

Signed-off-by: Tomas Tomecek <ttomecek@redhat.com>

README.md

@@ -127,6 +127,43 @@ passing `async=True`.
 You need to run `:UpdateRemotePlugins` in nvim for changes in the specifications
 to have effect. For details see `:help remote-plugin` in nvim.
 
+If you are working on your plugin locally, it may be desirable to run the
+plugin from a git repository directly without the need of installing or
+symlinking it.
+The easiest way to do this is to create a dedicated vimrc file just for sake of
+development of your plugin. If you are in a root of the git repo with the
+plugin, consider creating this vimrc file:
+```
+$ cat vimrc
+let &runtimepath.=','.escape(expand('<sfile>:p:h'), '\,')
+```
+
+It will append your current work directory to the runtime path so neovim is
+able to find and load your plugin.
+
+Then just run command `:UpdateRemotePlugins` and your plugin should be up and
+running.
+
+In case you run into some issues, you can list loaded plugins:
+```
+:scriptnames
+  1: ~/path/tp/your/plugin-git-repo/vimrc
+  2: /usr/share/nvim/runtime/filetype.vim
+  3: /usr/share/nvim/runtime/ftplugin.vim
+  4: /usr/share/nvim/runtime/indent.vim
+<trimmed for clarity>
+ 25: /usr/share/nvim/runtime/plugin/zipPlugin.vim
+ 26: ~/path/tp/your/plugin-git-repo/plugin/lucid.vim
+```
+
+You can also inspect the `runtimepath` like this:
+```
+:set runtimepath
+  runtimepath=~/.config/nvim,/etc/xdg/nvim,~/.local/share/nvim/site, <snip>
+,~/g/path/to/your/plugin-git-repo
+```
+
+
 #### Development
 
 If you change the code, you need to run