Remove Netlify support (#585)

* Remove Netlify

**Why**: A recent supply-chain attack on polyfill-dot-io
highlights the risks of linking to external domains for JS
like we were doing here with unpkg.com

Ref: https://sansec.io/research/polyfill-supply-chain-attack

I do not think we are using Netlify for this site, so it
seemed easier to remove the functionality entirely instead
of an alternative approach like vendoring the JS

* Update _articles/cloud-gov-pages.md

Co-authored-by: Andrew Duthie <[email protected]>

* Update _articles/cloud-gov-pages.md

Co-authored-by: Andrew Duthie <[email protected]>

---------

Co-authored-by: Andrew Duthie <[email protected]>

README.md

@@ -39,9 +39,3 @@ To check spelling:
 ```
 make spellcheck
 ```
-
-### NetlifyCMS
-
-The site is configured to use [NetlifyCMS](https://www.netlifycms.org/), so you can make changes via UI only by going to <https://handbook.login.gov/admin>.
-
-To use the CMS locally, while the server is running, view it locally at <http://localhost:4000/admin>.

_articles/cloud-gov-pages.md

@@ -8,11 +8,10 @@ subcategory: Code
 
 ## Overview
 
-Login.gov uses [Cloud.gov Pages][cloud-gov-pages] as its hosting provider for our [static sites][static-sites]. By becoming a user of the Login.gov organization in Cloud.gov Pages, you'll have access to build logs and settings configuration for each of our sites. Organization access also allows you to log in on sites which use Netlify CMS ([including this handbook!][handbook-admin]).
+Login.gov uses [Cloud.gov Pages][cloud-gov-pages] as its hosting provider for our [static sites][static-sites]. By becoming a user of the Login.gov organization in Cloud.gov Pages, you'll have access to build logs and settings configuration for each of our sites. Organization access also allows you to log in on sites which use Netlify CMS.
 
 [cloud-gov-pages]: https://cloud.gov/pages/
 [static-sites]: {% link _articles/github-gitlab.md %}#static-sites
-[handbook-admin]: {{ site.baseurl }}/admin/
 
 ## Requesting Access to Cloud.gov Pages