[Fix] - Fixed CLEAR_UNIFORM typo.

[Bubbus]

Pull Request Description

When merged this pull request will:

• Fix typos in gearscript readme.
• Add documentation for COPY_* macros in gearscript readme.

Release Notes

• Fixed typos in gearscript readme.
• Added documentation for COPY_* macros in gearscript readme.

IMPORTANT

• [x] Testing has been completed as neccessary, depending on the nature & impact of the changes.
• [x] The Release Notes section below must be filled out appropriately to explain the changes made in this PR. This section will be used in Framework Changelogs.
• [x] If the contribution affects the wiki, please include your changes in this pull request so the wiki is consistently updated.
• [x] Contribution Guidelines are read, understood and applied.
• [x] Title of this PR uses our standard template [Descriptor] - Add|Fix|Improve|Change|Make|Remove {changes}.

Resolves #151