Excludes some files from assets submodules

--> To rework with exclude & include statements, once Jekyll issue #4791 will be fixed

_config.yml

@@ -34,5 +34,16 @@ tipue_search:
 ## BUILD OPTIONS ##
 incremental: true
 exclude:
+  ## Explicit `exclude` rules for assets...
+  ## ... while Jekyll is broken (see issue #4791)
+  # github-widget submodule
+  - /github-widget/src/
+  - /github-widget/package.json
+  - /github-widget/package-lock.json
+  - /github-widget/README.md
+  # jekyll-tipue-search submodule
+  - /jekyll-tipue-search/_config.yml
+  - /jekyll-tipue-search/LICENSE
+  - /jekyll-tipue-search/README.md
   - /jekyll-tipue-search/search.html
 ## _____________ ##