made the pack completely portable and wrote relevent bat files to go with it

gitportable/usr/share/vim/vim91/compiler/README.txt

@@ -0,0 +1,13 @@
+This directory contains Vim scripts to be used with a specific compiler.
+They are used with the ":compiler" command.
+
+These scripts usually set options, for example 'errorformat'.
+See ":help write-compiler-plugin".
+
+To undo the effect of a compiler plugin, use the make compiler plugin.
+
+If you want to write your own compiler plugin, have a look at the other files
+for how to do it, the format is simple.
+
+If you think a compiler plugin you have written is useful for others, please
+send it to the vim-dev mailing list: <vim-dev@vim.org>