Update ConventionSetBuilder.cs - Spelling mistake TImplementaion

[Kloppie5]

ConventionSet.Remove`1 has a typeparam named TImplementaion; while other typeparams in ConventionSet use the correct name TImplementation

• I've specifically read the guidelines for contributing and seen the walkthrough
• I've not posted a comment on an issue with a detailed description of how I am planning to contribute and have not gotten approval from a member of the team, because its a typo fix
• The code builds, but the tests do not pass locally because I have a space in my computer name; though the change is a non-functional change, so there should logically be nothing wrong

[roji]

Thanks!