Fix a copy-and-paste error in man_docs.md

Thanks to @goern for reporting the error.

Fixes #188

man_docs.md

@@ -1,6 +1,6 @@
 # Generating Man Pages For Your Own cobra.Command
 
-Generating bash completions from a cobra command is incredibly easy. An example is as follows:
+Generating man pages from a cobra command is incredibly easy. An example is as follows:
 
 ```go
 package main