Merge pull request #141 from dunglas/patch-1

[doc] Mention to run modules_update_specs first

README.md

@@ -12,6 +12,9 @@ To use an ejabberd module coming from this repository:
 
 - You need to have ejabberd installed.
  
+- If you have not already done it, run `ejabberdctl modules_update_specs`
+  to retrieve the list of available modules.
+
 - Run `ejabberdctl module_install <module>` to get the source code and to
   compile and install the `beam` file into ejabberd's module search path.
   This path is either `~/.ejabberd-modules` or defined by the