doc: add the tool to check section marks in help documents
This patch adds "doc/check-seclevel.py" which checks below in help
documents:
- whether unknown or unavailable section marks are used or not
- whether appropriate section mark is used at sub-sectioning
It should be invoked in "doc" directory.
It checks all help documents of Mercurial (topics, commands,
extensions), if no file is specified by --file option.
With --file option, it checks contents of the specified file as help
document, for self testing purpose: -t/-c/-e/-C are used to specify
what kind of help document contents of the specified file is.
This checking is related to changeset 979b107eaea2.
os = <unloaded module 'os'>
os.system = <built-in function system>
os = <module 'os' from '?'>
util = <unloaded module 'util'>
util.system = <function system at 0x?>
util = <module 'mercurial.util' from '?'>
util.system = <function system at 0x?>
fred = <unloaded module 're'>
re = <unloaded module 'sys'>
fred = <unloaded module 're'>
fred.sub = <function sub at 0x?>
fred = <proxied module 're'>
re = <unloaded module 'sys'>
re.stderr = <open file '<whatever>', mode 'w' at 0x?>
re = <proxied module 'sys'>