fixes: #708

before:

After:

Action:

• In the code for getting the Table of Contents (TOC), we are calling a function twice:
• If the TOC is found on the first call, it will display normally.
• If the TOC length is 0 on the first call, we remove the TOC button and adjust the positions of the other buttons.
• If the TOC is found on the second call, the TOC button will reappear.
• If the TOC is not found in both calls, the TOC button remains removed, and the other buttons stay adjusted.

Note: There is another way to solve this by adjusting the entire navigation based on the TOC value, but it would require too many code changes in the repo. So, I went with this solution instead. If there's anything wrong, please let me know. Thanks