[docs] Code links are invalid

[gleehokie]

File: [docs/01_technical-overview.md](https://github.com/EOSIO/eosjs/blob/develop/docs/01_technical-overview.md)

The GitHub links in this document are made to the master branch, but the master branch changes, so the links are to invalid locations in the source code. For example, the last line of the document says "The transaction is then optionally broadcasted using JsonRpc's push_transaction." and "push_transaction" should link to the source code for push_transaction, but it does not since the code has change since the links were made. Most of the links to source code in this document, and perhaps other documents as well, are invalid.