Update usage.rst

Fixing the code display
Merge pull request #2 from Mibou/patch-1

Update usage.rst
Merge branch 'release/0.3.0'
Merge branch 'release/0.4.0'
Merge branch 'release/0.5.0'
alias support when creating indexes
delete by query support
Bumped version to 0.5.1
Merge branch 'hotfix/0.5.1' into develop