doc: vale fixups; clarifications clarify modal workflow, move bulk edit workflow from middle of edit item worflow to after. Clarify postfix expression use with Link items. Add rst() and markdown() to stext() and mark stext as depricated (maybe even this release cycle). More TAL examples. Refill some paragraphs to 65 character lines. Various other fixes pointed out by vale.

#!/usr/bin/env python
from __future__ import print_function
import zlib, base64, sys
print(base64.encodestring(zlib.compress(sys.stdin.read())))