Update documentation.md

.require() method definition lists a "uri" argument, when it should be "url". Change "uri" to "url".
Fixes a small typo in documentation.
Merge pull request #69 from c0bra/patch-1

Update documentation.md
Merge pull request #70 from Hemphill/patch-1

Fixes a small typo in documentation.
Keeping the index.html up to date with some fixes merged into documentation.md