Create linker documentation

[forestbelton]

On the object format wiki page, there is a broken link which refers to documentation regarding how relocation is performed on the tenyr architecture. While this information could be determined directly by examining the source code, I feel that a more concise & accessible explanation is warranted.

[kulp]

The linker wiki page is not very helpful yet, but it exists, and the wiki has just been opened up for collaborative editing.