fix many internal links

Fixed a number of internal links that need to
go to the GitHub site.

Ran `make www` to perform the above.

2013/dlowe/README.md

@@ -88,7 +88,7 @@ and with Apple clang version 15.0.0 (clang-1500.0.40.1) in 2023, we get:
 
 Which one is correct? :)
 
-NOTE: `make all` will compile [fun.c](fun.c) but to provide a different compiler
+NOTE: `make all` will compile [fun.c](%%REPO_URL%%/2013/dlowe/fun.c) but to provide a different compiler
 you can do something like:
 
 ``` <!---sh-->
@@ -113,13 +113,13 @@ A tiny implementation of command-line
     sparkline of file sizes: ▁▁▁▃▃▂▁▂▁▁▉
 ```
 
-NOTE: this has been provided in [slflen.sh](slflen.sh) so you can try:
+NOTE: this has been provided in [slflen.sh](%%REPO_URL%%/2013/dlowe/slflen.sh) so you can try:
 
 ``` <!---sh-->
     ./slflen.sh
 ```
 
-instead (which [try.sh](try.sh) also uses).
+instead (which [try.sh](%%REPO_URL%%/2013/dlowe/try.sh) also uses).
 
 
 ### Description