git: recognise level files

Set filetype for all (likely to be) levels to "wormylevel", so it is
possible to use custom handling for them.  Notably, for more detailed
diffs than 'binary files differ', users can use parse-wormedit output
for example:

	git config --global diff.wormylevel.textconv parse-wormedit

diff --git a/.gitattributes b/.gitattributes
new file mode 100644 (file)
index 0000000..09c0ee2
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1,2 @@
+*.86s diff=wormylevel
+*.lvl diff=wormylevel