Removed duplicate example, updated description of another example.

Removed cat file | grep pattern as cat file is unnecessary.  The command becomes 'grep pattern file' again - which is the same as the first example.

Updated #Advanced description to be more descriptive.
Merge branch 'patch-4' of https://github.com/adelviscio/cheat into adelviscio-patch-4

* 'patch-4' of https://github.com/adelviscio/cheat:
  Removed duplicate example, updated description of another example.
Fixed a minor typo in the grep cheatsheet.