Typos in the index script

[garyhuntddn]

Version of the script
dev branch

What is the current behavior?
Spelling mistakes:
paritions vs partitions
sequental vs sequential
partioned vs partitioned

If the current behavior is a bug, please provide the steps to reproduce.
See the code and #3518 for the fixes

What is the expected behavior?
Correct spelling :-)

Which versions of SQL Server and which OS are affected by this issue? Did this work in previous versions of our procedures?
all versions

[BrentOzar]

Thanks for the pull request! Looks good, merging into the dev branch, will be in the next release with credit to you in the release notes.