Rewrite clone examples to use HTTPS instead of SSH (#1963)

Let's use `https` instead of `ssh` in our cloning instructions because
some people might not have GitHub `ssh` configured on their machines,
while `https` works for everyone.

A user reported that they [have issues with cloning Playground
](#1961). I'm
not sure what the root cause of the issue is, but it prompted me to
rewrite the cloning instructions to remove friction from the setup
process.

## Testing Instructions (or ideally a Blueprint)

- review readmes
- try using the cloning command

README.md

@@ -84,15 +84,15 @@ The vanilla `git clone` command will take ages. Here's a faster alternative that
 only pull the latest revision of the trunk branch:
 
 ```
-git clone -b trunk --single-branch --depth 1 --recurse-submodules git@github.com:WordPress/wordpress-playground.git
+git clone -b trunk --single-branch --depth 1 --recurse-submodules https://github.com/WordPress/wordpress-playground.git
 ```
 
 ## Running WordPress Playground locally
 
 You also can run WordPress Playground locally as follows:
 
 ```bash
-git clone -b trunk --single-branch --depth 1 --recurse-submodules git@github.com:WordPress/wordpress-playground.git
+git clone -b trunk --single-branch --depth 1 --recurse-submodules https://github.com/WordPress/wordpress-playground.git
 cd wordpress-playground
 npm install
 npm run dev

packages/docs/site/docs/developers/23-architecture/18-host-your-own-playground.md

@@ -58,7 +58,7 @@ The most flexible and customizable method is to build the site locally.
 Create a shallow clone of the Playground repository, or your own fork.
 
 ```sh
-git clone -b trunk --single-branch --depth 1 --recurse-submodules git@github.com:WordPress/wordpress-playground.git
+git clone -b trunk --single-branch --depth 1 --recurse-submodules https://github.com/WordPress/wordpress-playground.git
 ```
 
 Enter the `wordpress-playground` directory.