Pluralizing the word commit(s)

Added a variable to hold the plural or singular form of "commit" depending on the number commits in the payload.
Merge pull request #1285 from adomokos/commit_singular_plural

Pluralizing the word commit(s)
Fix typo in the script description

Script description describes command top-commiters, when actual command is top-commiter
Command can be top-commiter or top-commiters
Merge pull request #1287 from scf2k/patch-1

Fix typo in the script description