fix: handle TOC token as case insensitive

[vikrantsinghthakur]

Motivation

Fix #1234
Placeholder tokens going through crowdin get converted to lowercase. This PR tries to check for both uppercase and lowercase placeholder token to be replaced with table.

Have you read the Contributing Guidelines on pull requests?

YES

Test Plan

Use crowdin to generate translation and check if table of contents has been added correctly

[facebook-github-bot]

Thank you for your pull request and welcome to our community. We require contributors to sign our Contributor License Agreement, and we don't seem to have you on file. In order for us to review and merge your code, please sign up at https://code.facebook.com/cla. If you are contributing on behalf of someone else (eg your employer), the individual CLA may not be sufficient and your employer may need the corporate CLA signed.

If you have received this in error or have any questions, please contact us at cla@fb.com. Thanks!

[yangshun]

Deploy preview for munseo-preview ready!

Built with commit 163622d

https://deploy-preview-1288--munseo-preview.netlify.com

[docusaurus-bot]

Deploy preview for docusaurus-preview ready!

Built with commit 163622d

https://deploy-preview-1288--docusaurus-preview.netlify.com

[vikrantsinghthakur]

Well I see the generated netlify build itself has the issue, even without translation. Let me take a look into it.

[jakebolam]

For sure @vikrantsinghthakur

[vikrantsinghthakur]

There were 2 builds generated for the PR with the same commit, munseo-preview and docusaurus-preview.
Table of contents was not generated for the former, while it seems to be working fine for the latter. This looks like a non deterministic outcome and I wonder why it occurred. Can anyone with more information about this enlighten me?

[endiliey]

Ignore the munseo-preview, thats the v2 build and lot of stuff is still wip on v2.

_{Sent with GitHawk}

[endiliey]

Instead of searching for the lower case version and the upper case version. We can do better with case insensitive search.

Regex allows this via “i” flag. Please refactor the code :)