Update contributing content (#6437)

## What are you changing in this pull request and why?

Need to update a few things:
* Cypress tests are no longer necessary because we have CI tests 
* Removing dev blog contribution docs - moving the blog

## Checklist
- [ ] I have reviewed the [Content style
guide](https://github.com/dbt-labs/docs.getdbt.com/blob/current/contributing/content-style-guide.md)
so my content adheres to these guidelines.
- [ ] The topic I'm writing about is for specific dbt version(s) and I
have versioned it according to the [version a whole
page](https://github.com/dbt-labs/docs.getdbt.com/blob/current/contributing/single-sourcing-content.md#adding-a-new-version)
and/or [version a block of
content](https://github.com/dbt-labs/docs.getdbt.com/blob/current/contributing/single-sourcing-content.md#versioning-blocks-of-content)
guidelines.
- [ ] I have added checklist item(s) to this list for anything anything
that needs to happen before this PR is merged, such as "needs technical
review" or "change base branch."
- [ ] The content in this PR requires a dbt release note, so I added one
to the [release notes
page](https://docs.getdbt.com/docs/dbt-versions/dbt-cloud-release-notes).
<!--
PRE-RELEASE VERSION OF dbt (if so, uncomment):
- [ ] Add a note to the prerelease version [Migration
Guide](https://github.com/dbt-labs/docs.getdbt.com/tree/current/website/docs/docs/dbt-versions/core-upgrade)
-->
<!-- 
ADDING OR REMOVING PAGES (if so, uncomment):
- [ ] Add/remove page in `website/sidebars.js`
- [ ] Provide a unique filename for new pages
- [ ] Add an entry for deleted pages in `website/vercel.json`
- [ ] Run link testing locally with `npm run build` to update the links
that point to deleted pages
-->

---------

Co-authored-by: Mirna Wong <[email protected]>

README.md

@@ -62,18 +62,3 @@ You can click a link available in a Vercel bot PR comment to see and review your
 
 Advisory:
 - If you run into an `fatal error: 'vips/vips8' file not found` error when you run `npm install`, you may need to run `brew install vips`. Warning: this one will take a while -- go ahead and grab some coffee!
-
-## Running the Cypress tests locally
-
-Method 1: Utilizing the Cypress GUI
-1. `cd` into the repo: `cd docs.getdbt.com`
-2. `cd` into the `website` subdirectory: `cd website`
-3. Install the required node packages: `npm install`
-4. Run `npx cypress open` to open the Cypress GUI, and choose `E2E Testing` as the Testing Type, before finally selecting your browser and clicking `Start E2E testing in {broswer}`
-5. Click on a test and watch it run!
-
-Method 2: Running the Cypress E2E tests headlessly
-1. `cd` into the repo: `cd docs.getdbt.com`
-2. `cd` into the `website` subdirectory: `cd website`
-3. Install the required node packages: `npm install`
-4. Run `npx cypress run`