INSTALL.md: Add Watcom instructions and update Windows documentation URLs (#524)

This commit adds instructions on how to use the WATCOM compiler to build c-ares. This was just tested on c-ares-1.19.1 and works well.

While going through the links for the C Runtime documentation for Windows systems, I discovered that all three of the KB articles that were linked are now nonexistent. This commit replaces KB94248 with the current replacement available on Microsoft's website, which also makes the other two KB articles obsolete.

Fix By: Douglas R. Reno (@renodr)

INSTALL.md

@@ -291,16 +291,12 @@ As a general rule, building a DLL with static CRT linkage is highly
 discouraged, and intermixing CRTs in the same app is something to
 avoid at any cost.
 
-Reading and comprehension of Microsoft Knowledge Base articles
-KB94248 and KB140584 is a must for any Windows developer. Especially
+Reading and comprehension of the following Microsoft Learn article
+is a must for any Windows developer. Especially
 important is full understanding if you are not going to follow the
 advice given above.
 
- - [KB94248](http://support.microsoft.com/kb/94248/en-us) - How To Use the C Run-Time
-
- - [KB140584](http://support.microsoft.com/kb/140584/en-us) - How to link with the correct C Run-Time (CRT) library
-
- - [KB190799](http://msdn.microsoft.com/en-us/library/ms235460) - Potential Errors Passing CRT Objects Across DLL Boundaries
+ - [Use the C Run-Time](https://learn.microsoft.com/en-us/troubleshoot/developer/visualstudio/cpp/libraries/use-c-run-time)
 
 If your app is misbehaving in some strange way, or it is suffering
 from memory corruption, before asking for further help, please try
@@ -397,6 +393,21 @@ You can build and install c-ares using [vcpkg](https://github.com/Microsoft/vcpk
 
 The c-ares port in vcpkg is kept up to date by Microsoft team members and community contributors. If the version is out of date, please [create an issue or pull request](https://github.com/Microsoft/vcpkg) on the vcpkg repository.
 
+WATCOM
+=====
+
+To build c-ares with OpenWatcom, you need to have at least version 1.9 of OpenWatcom. You can get the latest version from [http://openwatcom.org/ftp/install/](http://openwatcom.org/ftp/install/). Install the version that corresponds to your current host platform.
+
+After installing OpenWatcom, open a new command prompt and execute the following commands:
+
+```
+  cd \path\to\cmake\source
+  buildconf.bat
+  wmake -u -f Makefile.Watcom
+```
+
+After running wmake, you should get acountry.exe, adig.exe, ahost.exe, and the static and dynamic versions of libcares.
+
 PORTS
 =====