Fix typos in documentation

Fix typos in documentation

* doc/misc/vhdl-mode.texi (Custom Indentation Functions):
* doc/misc/url.texi (Customization):
* doc/misc/tramp.texi (Overview):
* doc/misc/srecode.texi (Developing Template Functions):
* doc/misc/sieve.texi (Sieve Mode):
* doc/misc/reftex.texi (Options - Creating Citations):
* doc/misc/org.texi (Cooperation, Conflicts):
* doc/misc/gnus.texi (Misc Group Stuff):
* doc/misc/eshell.texi (Bugs and ideas):
* doc/misc/calc.texi (Summary):
* doc/man/emacsclient.1:
* doc/lispref/os.texi (Security Considerations):
* doc/lispref/control.texi (pcase Macro):
* CONTRIBUTE: Fix typos.  Reported by Mak Kolybabi
<mak@kolybabi.com>  (Bug#32853)