Update README.md (#70)

* Update README.md

Updated the README with clearer information: 

- an information about the refresh time -- I almost created a bug, because I'm a beginner on tmux and I didn't know this variable; so I think that an informative line about this can be useful
- a modification of an example that I didn't find necessarily clear because it didn't use the same context as the example given in the "Getting started" section

* Update README.md

Improve the line about status-interval

README.md

@@ -57,6 +57,12 @@ you run or when you switch windows, however it won't refresh automatically, nor
 
 Note that `tmux v2.1` was released in 2015 so you're probably better off updating to a more recent version anyway 🙂.
 
+In case gitmux takes too long to refresh, try to decrease the value of the `status-interval` option. A reasonable value is 2 seconds, which you can set in `.tmux.conf` with:
+
+    set -g status-interval 2
+
+Check out [tmux man page](https://www.man7.org/linux/man-pages/man1/tmux.1.html#OPTIONS) for more details.
+
 ## Customizing
 
 `gitmux` output can be customized via a configuration file in YAML format.
@@ -98,9 +104,9 @@ First, save the default configuration to a new file:
 
     gitmux -printcfg > .gitmux.conf
 
-Modify the line in `.tmux.conf`, passing the path of the configuration file as argument to `gitmux`
+Modify the line in `.tmux.conf`, passing the path of the configuration file as argument to `gitmux` via the `-cfg` flag
 
-    gitmux -cfg .gitmux.conf
+    set -g status-right '#(gitmux -cfg .gitmux.conf "#{pane_current_path}")'
 
 Open `.gitmux.conf` and modify it, replacing symbols, styles and layout to suit your needs.
 
@@ -222,7 +228,6 @@ This is the list of additional configuration `options`:
 
 Please report anything by [filing an issue](https://github.com/arl/gitmux/issues/new).
 
-
 ## Contributing
 
 Pull requests are welcome.