Update provider doc (#11)

docs/index.md

@@ -8,6 +8,11 @@ description: |-
 
 # stackit Provider
 
+The STACKIT provider is the official Terraform provider to integrate all the resources developed by STACKIT.
+
+# Authentication
+
+Currently, only the *token flow* is supported. The Terraform provider will first try to find a token in the `STACKIT_SERVICE_ACCOUNT_TOKEN` env var. If not present, it will check the credentials file located in the path defined by the `STACKIT_CREDENTIALS_PATH` env var, if specified, or in `$HOME/.stackit/credentials.json` as a fallback. If the token is found, all the requests are authenticated using that token.
 
 
 ## Example Usage

website/docs/index.html.markdown

@@ -1,29 +0,0 @@
-The STACKIT provider is the official Terraform provider to integrate all the resources developed by STACKIT.
-
-## Authentication
-
-Before you can start using the client, you will need to create a STACKIT Service Account in your project and assign it the appropriate permissions (i.e. `project.owner`).
-
-After the service account has been created, you can authenticate to the client using the Token flow.
-
-### Token flow
-There are multiple ways to provide the token to the Terraform provider:
-- Pass it to the provider directly:
-```
-provider "stackit" {
-   service_account_token = "[TOKEN]"
-}
-```
-
-- Set it in an environment variable:
-```bash
-export STACKIT_SERVICE_ACCOUNT_TOKEN="[TOKEN]"
-```
-
-- Create a file `~/.stackit/credentials.json` with the content:
-```json
-{
-	"STACKIT_SERVICE_ACCOUNT_TOKEN": "[TOKEN]"
-}
-```
-> To read from another location, either pass the file path to the provider using the variable `credentials_path`, or set the environment variable `STACKIT_CREDENTIALS_PATH` as the file path.