Merge pull request #428 from datamweb/rename-file-api-tokens

docs: rename file `api-tokens.md` to `api_tokens.md`

Author: datamweb

docs/guides/api-tokens.md docs/guides/api_tokens.mddocs/guides/api-tokens.md renamed to docs/guides/api_tokens.md

@@ -11,4 +11,4 @@
 * [Customization](customization.md)
 
 Guides:
-* [Protecting an API with Access Tokens](guides/api-tokens.md)
+* [Protecting an API with Access Tokens](guides/api_tokens.md)