Incorrect command to preview local docs changes in contributing.md

[dianacheung]

Describe the bug

In the contributing guide (contributing.md), it currently states:

To preview your changes locally, run this command from the docs/ folder:
https://redocly.com/docs/cli/

The above command is incorrect and will result in an error stating that it is not a valid command.

To Reproduce
Steps to reproduce the behavior:

1. Navigate to the docs/ folder
2. Run https://redocly.com/docs/cli/
3. See error

Expected behavior

The correct command to run is: redocly preview
Running the above command will start a local preview server for the docs/ folder. By default, see the docs preview at http://localhost:4000 or http://127.0.0.1:4000.

Note: Make sure redocly is already installed. Include link to installation instructions https://redocly.com/docs/cli/installation/.

[dianacheung]

I can work on this issue.

[dianacheung]

Hi @lornajane, PR #1533 awaiting review approval. Thanks.

[tatomyr]

I believe this on is resolved by #1533.