Merge pull request #297 from bsipocz/BUG_default_branch_name

BUG: fix name of default branch for edit-on-github

Author: consideRatio

doc/conf.py

@@ -83,7 +83,7 @@
 html_context = {
     "github_user": "jupyterhub",
     "github_repo": "binder",
-    "github_version": "master",
+    "github_version": "main",
     "doc_path": "doc",
     "source_suffix": source_suffix,
 }