Document minimal setup

Steps so far:
* Sign up at https://admin.mistral.ai.
* Open the "La Platforme" page.
* In the sidebar, under "Workspace" section, open "API keys".
* If the account has not enabled API access yet, click through to update the account to either "Experiment" mode or a paid subscription.
* Back on the API keys page (https://console.mistral.ai/api-keys) click "Create new key".
* Provide a name for the API key and an expiration date, if desired; click "Create new key".
* Once the API key is generated, copy the string.
* On the Keys admin page (admin/config/system/keys) click "Add key".
* Fill in a key name and description as appropriate.
* Set the "Key type" to "Authentication".
* Set the "Key provider" as appropriate for the individual scenario; a simple option is to set it to "Configuration".
* Set the "Value" as appropriate for the individual scenario; a simple option is to paste in the API key generated earlier.
* Click "Save" to save the API key.
* Open the Huggingface admin page (admin/config/ai/providers/huggingface).
* On the "Huggingface Access Token" field select the API key item that was created above.
* Complete the reset of the setup as necessary.

Problem: When setting up an initial environment for testing it's not clear what the "endpoint" value should be?

I opened a separate issue for the endpoint issue: ✨ Document what the endpoint should be set to Active

Steps so far:
* Sign up at https://huggingface.co and go through the steps to confirm the account.
* Open the profile page.
* In the sidebar open the "Access tokens" page: https://huggingface.co/settings/tokens
* Click on "Create new token".
* Provide a name for the token and select the appropriate permissions and click "Create token".
* Once the token is generated, copy the string.
* On the Keys admin page (admin/config/system/keys) click "Add key".
* Fill in a key name and description as appropriate.
* Set the "Key type" to "Authentication".
* Set the "Key provider" as appropriate for the individual scenario; a simple option is to set it to "Configuration".
* Set the "Value" as appropriate for the individual scenario; a simple option is to paste in the API key generated earlier.
* Click "Save" to save the API key.
* Open the Huggingface admin page (admin/config/ai/providers/huggingface).
* On the "Huggingface Access Token" field select the API key / token item that was created above.
* Complete the reset of the setup as necessary.

Note, it's not clear what permissions are necessary.