Corrected example code, cleared up token confusion (#12177)

The adjustment was made after I spent a few minutes scratching my head, I have done the following: 

* Updated the 'provider' block in the first example code to be 'token' instead of 'access_key' - Didn't work previously. 
* Clarified locations of both 'access_key' and 'token' within the Scaleway panel, and appropriate naming.
* Removed "empty" section in example block at the bottom, as this fails with an error when attempted.

Overall I think this increases readability. I have tested this against my own Scaleway account.

website/source/docs/providers/scaleway/index.html.markdown

@@ -23,8 +23,8 @@ Here is an example that will setup the following:
 
 ```hcl
 provider "scaleway" {
-  organization = ""
-  access_key   = ""
+  organization = "<YOUR-ACCESS-KEY>"
+  token        = "<YOUR-GENERATED-TOKEN>"
   region       = "par1"
 }
 
@@ -75,22 +75,27 @@ resource "scaleway_security_group_rule" "https_accept" {
 }
 ```
 
-You'll need to provide your Scaleway organization access key
-(available in Scaleway panel in *Credentials > Tokens > access key*)
-and token (you can generate it in the same section), so that Terraform can connect.
-If you don't want to put credentials in your configuration file,
+You'll need to provide your Scaleway organization **access key** and **token**.
+
+Your access key can be found on your Scaleway control panel, in the *Credentials* 
+tab of the management panes. It is under the *Tokens* subsection, but is labelled 
+seperately as **access key**.
+
+Your **token** can be generated by selecting to "Create new token" under the same
+subsection as above. This does not require further input, but giving each token a 
+friendly-name is suggested.
+
+If you do not want to put credentials in your configuration file,
 you can leave them out:
 
 ```
 provider "scaleway" {
-  organization = ""
-  token        = ""
   region       = "par1"
 }
 ```
 
 ...and instead set these environment variables:
 
 - **SCALEWAY_ORGANIZATION**: Your Scaleway `organization` access key
-- **SCALEWAY_TOKEN**: Your API access `token`
+- **SCALEWAY_TOKEN**: Your API access `token`, generated by you
 - **SCALEWAY_REGION**: The Scaleway region