tools/raml2html/README.md: Update dir paths

docs/api/rest_api_reference/ → docs/api/rest_api/rest_api_reference/

Author: adriendupuis

tools/raml2html/README.md

@@ -17,7 +17,7 @@ composer install;
 To generate static HTML from RAML definitions, use the following code from project root:
 
 ```sh
-php tools/raml2html/raml2html.php build --non-standard-http-methods=COPY,MOVE,PUBLISH,SWAP -t default -o docs/api/rest_api_reference/output/ docs/api/rest_api_reference/input/ez.raml
+php tools/raml2html/raml2html.php build --non-standard-http-methods=COPY,MOVE,PUBLISH,SWAP -t default -o docs/api/rest_api/rest_api_reference/output/ docs/api/rest_api/rest_api_reference/input/ez.raml
 ```
 
 Note: If PHP 7.2 is not the default PHP, please, adapt.