BIP-0001 Should be labeled as "Process" Type

Previously BIP-0001 listed in its header preamble that is was a "Standards Track" type proposal. This conflicts with both its own definition of "Standards Track" proposal as well as the type listed in PEP-0001 of which BIP-0001 is based on.

Defitions of each type of proposal:

A Standards Track BIP describes any change that affects most or all Bitcoin implementations.

An Informational BIP describes a Bitcoin design issue, or provides general guidelines or information to the Bitcoin community, but does not propose a new feature.

A Process BIP describes a process surrounding Bitcoin, or proposes a change to (or an event in) a process. Specifically: "Any meta-BIP is also considered a Process BIP."

Based on these definitions BIP-0001 should have always been labeled as a "Process" BIP and this patch corrects this.