Change " to `

As done in the description of `master`

data/glossaries/external.yml

@@ -401,7 +401,7 @@
 - term: main
   description: >-
     The default development branch. Whenever you create a Git repository, a
-    branch named "main" is created, and becomes the active branch. In most
+    branch named `main` is created, and becomes the active branch. In most
     cases, this contains the local development, though that is purely by
     convention and is not required.
 - term: master