FYI, you should replace DocsHandler with net/http's FileServer.
Reasons: 1) the implementation is not vulnerable to path traversal attacks (i.e. if url.Path == "/../../../../../etc/passwd"). 2) It automatically handles index.html 3) It uses "/etc/mime.types" and other system files to automatically set mime types 4) It streams the file back instead of reading it all into memory.
Building an API in Go feels -very- robust because of the strong typing and the strict compiler. After a while you'll discover the strength of interfaces and be pleasantly surprised. Combined with the performance boost, I can't think of a better language to write an API in.