doc: Use relative links in generated index.html when possible

doc/support/generate.sh

Index: doc/support/generate.sh
diff --git a/doc/support/generate.sh b/doc/support/generate.sh
index f5785c6447c72eefc41618e656bd0a2ef88e91fb..f85e4d3c4e39e6f6c90edfc6a09b3a8d810002f2 100755
--- a/doc/support/generate.sh
+++ b/doc/support/generate.sh
@@ -43,7 +43,10 @@ done
 
 # Move doc/index.html to index.html, adjusting relative paths to other files in
 # doc.
+base_url=https://crashpad-home.appspot.com/
 ${sed_ext} -e 's%<a href="([^/]+)\.html">%<a href="doc/\1.html">%g' \
+    -e 's%<a href="'"${base_url}"'">%<a href="index.html">%g' \
+    -e 's%<a href="'"${base_url}"'%<a href="%g' \
     < "${output_dir}/doc/index.html" > "${output_dir}/index.html"
 rm "${output_dir}/doc/index.html"