fix more broken markdown links

We fix more markdown links in markdown files that refer to files
internally to the web site.

Added tmp tools to find and print various markdown links:

* `tmp/md-links.sh` - print all markdown links
* `tmp/md-token-links.sh` - print all markdown links that start with a **%%TOKEN%%**
* `tmp/md-local-links.sh` - print all markdown links to a local file
* `tmp/md-link-paths.sh` - print local file paths referenced in markdown links

Fixed a number of markdown formatting problems with `thanks-for-help.md`.
Fixed markdown links to files in `thanks-for-help.md`.  Improved
heading levels in `thanks-for-help.md`, and made entry sections consistent.

Changed all markdown links that end in "))" to end in a better way.

Explained in `markdown.md` why we are avoiding markdown links that
end in "))".

Ran `make www` to perform the above.

TODO: Fix stuff we broke by mistake doing the above.

TODO: Fix more broken markdown links.

2001/anonymous/README.md

@@ -123,7 +123,7 @@ The build script should give an example command to compile the program.
 ### Features
 
 [Basic Block](https://en.wikipedia.org/wiki/Basic_block)
-[Cache](https://en.wikipedia.org/wiki/Cache_(computing)): Rather than
+[Cache](https://en.wikipedia.org/wiki/Cache_(computing)): Rather than
 translating each instruction individually the dynamic binary translator
 generates a translation for an entire basic block of subject code.  Having
 translated a block once, the target code generated will be stored for the
@@ -138,7 +138,7 @@ The program runs [dynamically
 linked](https://en.wikipedia.org/wiki/Dynamic_linker) [ELF
 binaries](https://en.wikipedia.org/wiki/Executable_and_Linkable_Format), and
 when the subject program attempts to make a call to a standard
-[library](https://en.wikipedia.org/wiki/Library_(computing)), the translator
+[library](https://en.wikipedia.org/wiki/Library_(computing)), the translator
 attempts to make an appropriate call to the native system libraries on the
 target machine.  This involves mangling between different calling conventions,
 etc.
@@ -209,9 +209,9 @@ on to the next line of code.
 Due to space limitations only a handful of instructions are supported; these
 instructions which are supported are supported in somewhat non-conventional
 ways: chunks of the architecture (e.g. flags) are just ignored, the ELF
-[loader](https://en.wikipedia.org/wiki/Loader_(computing)) does not really load
+[loader](https://en.wikipedia.org/wiki/Loader_(computing)) does not really load
 the [ELF binary](https://en.wikipedia.org/wiki/Executable_and_Linkable_Format),
-the target [library linking](https://en.wikipedia.org/wiki/Linker_(computing))
+the target [library linking](https://en.wikipedia.org/wiki/Linker_(computing))
 can only pass up to 3 parameters to the target library function, etc.
 
 In short, please consider this a full disclaimer for any bug that may