Merge pull request tmux-plugins#149 from ploth/patch-1

Update README.md

Author: bruno-

README.md

@@ -45,7 +45,7 @@ That's it!
 ### Installing plugins
 
 1. Add new plugin to `~/.tmux.conf` with `set -g @plugin '...'`
-2. Press `prefix` + <kbd>I</kbd> (capital I, as in **I**nstall) to fetch the plugin.
+2. Press `prefix` + <kbd>I</kbd> (capital i, as in **I**nstall) to fetch the plugin.
 
 You're good to go! The plugin was cloned to `~/.tmux/plugins/` dir and sourced.