Updated Running Doc Server section in CONTRIBUTE.md, fix for npm start in windows

[shermanhuman]

Description

CONTRIBUTING.md

• changed 'navigate to project root directory' to 'navigate to docs subdirectory'

It seems like the process has changed, since you can't run npm from the root directory, there's no package.json there. So I updated the instructions to start from the 'doc' subdir.

• Added 'npm install' to instructions

This is required for new installs, right?

package.json

• Changed npm start script to use double quotes for Windows compatibility

'nodemon' has some limitations using --exec on windows. Double quotes are required for Windows users.

Checklist

• [x] The base branch of this PR is dev, rather than main
• [x] The relevant docs, if any, have been updated or created

Testing

• Viewed CONTRIBUTING doc in browser on my fork.
• Tested 'npm run start' in Windows 11 and MacOS Sonoma environments.

Follow the instructions in the updated doc to test:

1. Open your terminal and navigate to the docs subdirectory of the project. The docusaurus.config.js file you'll see there is a sign you're in the right place.

2. Run the following command to install the necessary dependencies for the documentation server:

   npm install
   

3. Run the following command to start the documentation server:

   npm run start