Add a global version number.

So the main() and About dialog can use it.

notes/README.git

@@ -7,3 +7,17 @@
 % git merge better_refresh      # Merge a branch back with the mainline.
 
 
+Git token refreshing.
+
+    erniep@gracie:/peak/src/seer$ gh auth login
+    ? What account do you want to log into? GitHub.com
+    ? What is your preferred protocol for Git operations? HTTPS
+    ? How would you like to authenticate GitHub CLI? Paste an authentication token
+    Tip: you can generate a Personal Access Token here https://github.com/settings/tokens
+    The minimum required scopes are 'repo', 'read:org', 'workflow'.
+    ? Paste your authentication token: ****************************************
+    - gh config set -h github.com git_protocol https
+    ✓ Configured git protocol
+    ✓ Logged in as epasveer
+    erniep@gracie:/peak/src/seer$
+