Maint: Update docs for schedule type and metaparameter

The wording of these was out of date and somewhat strange.
Maint: Improve/reduce documentation of relationship metaparemeters

These descriptions were too wordy and too inconsistent. I'm imposing a format on
them so they all look alike, and a casual reader can tell how many there are and
how their behaviors differ. I'm also adding links to the more detailed
documentation.
Maint: Standardize docs for refresh behavior in resource types; clarify exec docs

Service/mount/exec already documented that they do the refresh thing, but it
wasn't organized in a predictable way. I'm imposing a convention of a bold
"Refresh" label, a reminder of where events come from, and a description of what
that type does when it gets one.

This commit also adds a lot more detail on how execs respond to refresh, since
it's actually really complicated and not the least bit intuitive. I also reworded
some of the older language near the top of the exec type, while I was in there.
Maint: Clarify docs for stage type and metaparameter

This was pretty disorganized and confusing. Now it's less so!
(packaging) Update PUPPETVERSION to 3.4.2
(PUP-1211) Force registry value encoding to match code page

Ruby uses ANSI versions of Win32 APIs to read values from the registry. The
encoding of these strings depends on the active code page. However, ruby
incorrectly sets the string encoding to US-ASCII.[1]

As a result, if you try to perform a regex match on the string, and the string
contains the registered trademark symbol, 0xAE, then ruby will raise an error
saying 'Invalid byte sequence in US-ASCII'

This commit forces the encoding of REG_SZ, REG_EXPAND_SZ, and REG_MULTI_SZ to
the encoding for the active code page. So if the active code page is 1252, the
ruby encoding will be `Encoding::CP1252`.

See https://bugs.ruby-lang.org/issues/8943
Merge pull request #2229 from joshcooper/issue/stable/PUP-1211-registry-encoding

(PUP-1211) Force registry value encoding to match code page
Merge pull request #2156 from nfagerlund/docs_metaparams_schedule

Docs: Schedule, stage, and other metaparams