bip3: Fix capitalization and drop footnote

Author: murchandamus

bip-0003.md

@@ -30,7 +30,7 @@ BIP types more clearly, and generalizes the BIP process to fit the community
 
 ### What is a BIP?
 
-BIPs are improvement proposals for Bitcoin[^capitalization]. The main topic is information and technologies that support and expand the utility of the bitcoin
+BIPs are improvement proposals for Bitcoin. The main topic is information and technologies that support and expand the utility of the Bitcoin
 currency. Most BIPs provide a concise, self-contained, technical description of one new concept, feature, or standard.
 Some BIPs describe processes, implementation guidelines, best practices, incident reports (e.g.,
 [BIP 50](bip-0050.mediawiki)), or other information relevant to the Bitcoin community. However, any topics related to
@@ -41,7 +41,7 @@ documenting design decisions that have gone into implementations. BIPs may be su
 
 The scope of the BIPs
 repository is limited to BIPs that do not oppose the fundamental principle that Bitcoin constitutes a peer-to-peer
-electronic cash system for the bitcoin currency.
+electronic cash system for the Bitcoin currency.
 
 ### BIP Ownership
 
@@ -626,9 +626,6 @@ feedback, and helpful comments.
     has frequently led to confusion, with authors using the date of opening the pull request, the date they started
     writing their proposal, the date of number assignment (as prescribed), or various other dates. Aligning the name of
     the header and the text in the preamble template with the descriptions will reduce the confusion.
-[^capitalization]: **When is Bitcoin capitalized and when is it lowercased?**  
-    This document uses capitalized Bitcoin to refer to the system, network and abstract concept, and only uses lowercase
-    bitcoin to refer to units of the bitcoin currency.
 [^standard-track]: **Why was the Specification type introduced?**  
     The definitions of Informational and Standards Track BIPs caused some confusion in the past. Due to Informational
     BIPs being described as optional, Standards Track BIPs were sometimes misunderstood to be generally recommended.