add instructions for local instance (#171)

* add instructions for local instance

* use yarn

---------

Co-authored-by: Atul-Butola <[email protected]>

Author: 2 people

README.md

@@ -35,7 +35,7 @@ fern generate --version <version>
 
 In the root of this repository:
 ```
-cd custom-implementation/ && npm i && npm run build && cd ..
+cd custom-implementation/ && yarn && yarn build && cd ..
 fern docs dev
 ```
 
@@ -56,4 +56,4 @@ When the action completes, it adds the `stylecheck-complete` tag. If you want st
 To run the script locally and not as part of a PR, set your environment variable `LLM_TOKEN` to your PAT from [OpenWebUI](https://openwebui.dev.devrev-eng.ai/) > **Settings** > **Account** > API Keys. Include the supplemental developer style rules with the `--style` option.
 ```
 python stylecheck.py --style=style/developer.md <path/to/file.mdx>
-```
+```