update tox.ini to exclude github view files (blobs) that break the link check

Author: DaltheCow

tox.ini

@@ -66,8 +66,8 @@ description = Run link checks for root and docs markdown files
 deps =
     .[dev]
 commands =
-    mkdocs-linkcheck ./
-    mkdocs-linkcheck docs/
+    mkdocs-linkcheck ./ --exclude 'https://github\.com/.*/blob/.+\.md'
+    mkdocs-linkcheck docs/ --exclude 'https://github\.com/.*/blob/.+\.md'
 
 
 [testenv:build]