Update Arcade to 1.0

[nbarbettini]

This PR:

• Updates arcadejs to the latest release (1.0.0)
• Fixes breaking changes in client methods/fields
• Adds link for getting an API key to Arcade setup section
• Clarifies that auth requires either Arcade, or your own Twitter/LinkedIn apps

[bracesproul]

lgtm, im going to clone locally & run my tests and granted it all works I'll approve & merge.

thanks for doing this!!

[bracesproul]

Suggested change

	Regardless of the method you choose, you will need to set these environment variables in your `.env` file:
	- `TWITTER_USER_ID` - The ID/email of the Twitter account you want to use to post to Twitter.
	- `LINKEDIN_USER_ID` - The ID/email of the LinkedIn account you want to use to post to LinkedIn.
	#### Arcade setup
	Create an Arcade account [here](https://www.arcade.dev). After you register, [get an Arcade API key](https://docs.arcade.dev/home/quickstart?lang=typescript). Set this value as `ARCADE_API_KEY` in your `.env` file.
	#### Arcade setup
	Create an Arcade account [here](https://www.arcade.dev). After you register, [get an Arcade API key](https://docs.arcade.dev/home/quickstart?lang=typescript). Set this value as `ARCADE_API_KEY` in your `.env` file.
	Then, you will need to set these environment variables in your `.env` file:
	- `TWITTER_USER_ID` - The ID/email of the Twitter account you want to use to post to Twitter.
	- `LINKEDIN_USER_ID` - The ID/email of the LinkedIn account you want to use to post to LinkedIn.

Using the linkedin/twitter api directly doesn't req this since you set the access tokens/user urn (linkedin) for the specific user you authorized in the .env

[bracesproul]

worked like a charm. thanks!

[nbarbettini]

Thanks for the review and the catch @bracesproul!