Updated/Added/Fixed PHPDoc Blocks.

- Fixed typo(s)
- Fixed blocks having wrong format (jumbled types, missing params)
- Fixed doc blocks (`//` to blocks for maintaining one style)
- Added missing types (`array`, `string`, `boolean`, etc.)
- Added missing doc blocks (with explanation)
- Added missing `@params`
- Added reference to other methods (Referenced using `@see` wherever
required)
- Formatted doc blocks (grouping, line breaks, missing vars)
- Removed additional space(s)