Improve env confmap clarity (#653)

Author: bryan-aguilar

src/docs/components/confmap-providers.mdx

@@ -38,7 +38,7 @@ The ADOT collector support the following types of confmap providers: file, env,
 * scheme: `env`. Scheme is optional.
 * description: Retrieves configuration from an environment variable.
 * examples:
-  * `env:ENVIRONMENT_FILE_NAME`
+  * `env:ENVIRONMENT_VARIABLE_NAME`
 
 ### YAML provider