Merge branch 'ta/hash-function-transition-doc'

Update formatting and grammar of the hash transition plan documentation, plus some updates. * ta/hash-function-transition-doc: doc: use https links doc hash-function-transition: move rationale upwards doc hash-function-transition: fix incomplete sentence doc hash-function-transition: use upper case consistently doc hash-function-transition: use SHA-1 and SHA-256 consistently doc hash-function-transition: fix asciidoc output