update introductory paragraphs to remove any indication that plone.api will go away.

give indication of the versioning policy when discussing the stability of the package

minor spelling fix
omit needless words

clean up the sentence structure a bit.
clean up and consolidate english in about.rst
fixing this formatted string block.  It still fails to appear due to odd css.  we need to review that
fixing the english for this section of the docs
port fixed english from index.rst to README.rst
merge on a single format and wording for the admonition against reading on
github.  Add it to pages that were missing it as well
fix minor typo
english fixes

standardize wording

fix error in wording for local roles revoke
fix :mod: reference per @zupo
remove :ref: per @zupo

fix up phrasing with suggestions from @zupo
add reference to env chapter, per @zupo
fix typo per @zupo
use initial-caps version of Dexterity and Archetypes names by convention (per @zupo)
fix wording per @zupo
point to correct pages