[Proposal] Track Submodule pymc-examples Git Fix (#4375)

* 📌 Track submodule pymc-examples to main branch
* Configure .gitmodules to specify branch for submodule
* closes #4357

* 📌 Track submodule pymc-examples to main branch
* Configure .gitmodules to specify branch for submodule
* closes #4357

* ⬆️ Commit latest main branch submodule pymc-examples
* Updated .gitattributes file
* git submodule sync
* switch branch
* go to parent module, and commit

* :pin: Change git submodule update command for docs/source/pymc-examples

Author: CloudChaoszero

Diff for: .gitmodules

@@ -1,3 +1,4 @@
 [submodule "docs/source/pymc-examples"]
 	path = docs/source/pymc-examples
-	url = [email protected]:pymc-devs/pymc-examples.git
+	url = https://github.com/pymc-devs/pymc-examples.git
+        branch = main

Diff for: build_and_deploy_docs.sh

@@ -3,7 +3,7 @@
 latesttag=$(git describe --tags `git rev-list --tags --max-count=1`)
 echo checking out ${latesttag}
 git checkout ${latesttag}
-git submodule update --init --recursive
+git submodule update --remote
 pushd docs/source
 make html
 ghp-import -c docs.pymc.io -n -p _build/html/