codespell: Ignore the THANKS file and debbugs.gnu.org URL

This way "codespell -i 0" is silent.

This is the first commit from
#93
with trivial edits by Lasse Collin.

.codespellrc

@@ -3,7 +3,8 @@
 # Skip all translation files and a few other autogenerated files.
 # The autotool files should have their typos fixed in the upstream, but
 # until then we will blacklist them here.
-skip = *.po,*.pot,./po4a/man,./doc/api,./configure,./autom4te.cache,./m4/libtool.m4,./build-aux/depcomp,./build-aux/ltmain.sh,./build-aux/config.guess,./build-aux/config.rpath,./m4/po.m4,./build-aux/config.sub
+# THANKS contains names, some do trigger codespell.
+skip = *.po,*.pot,./po4a/man,./doc/api,./configure,./autom4te.cache,./m4/libtool.m4,./build-aux/depcomp,./build-aux/ltmain.sh,./build-aux/config.guess,./build-aux/config.rpath,./m4/po.m4,./build-aux/config.sub,THANKS
 
 # Ignore false positive matching words. Ideally codespell would allow
 # ignoring words for specific files, but that does not appear to be
@@ -22,3 +23,6 @@ builtin = clear,rare,informal,usage,names
 # Always default to highest interactive level to avoid accidentally
 # changing a false positive or picking the wrong replacement.
 interactive = 3
+
+# Ignore a URL with debbugs.
+ignore-regex = \bhttps://debbugs\.gnu\.org\b