fix(docs): correct heading hierarchy and Table of Contents in quickstart samples

[Srinu346]

What has changed?

This PR fixes incorrect heading hierarchies across multiple documentation pages that were causing the right-side Table of Contents to appear misaligned and inconsistent. Headings have been updated to follow a proper structure, and section titles were corrected so the Table of Contents accurately reflects the page content wherever the issue was repeated.

This PR resolves #3713

Type of change

• Documentation update (if none of the other choices apply).

How Has This Been Tested?

• Ran npm run build to ensure the documentation builds successfully without errors.
• Manually verified that headings and the left-side Table of Contents are properly aligned and consistent across affected pages.
• Visually inspected pages to confirm improved navigation and structure.

Checklist:

• My code follows the style guidelines of this project.
• I have performed a self-review of my own code.

Screenshots

• Before

• After

[Achanandhi-M]

Hey @Srinu346 can you please add video of your changes, i couldn't able to see any changes from the screenshot

[Srinu346]

@Achanandhi-M sir,

Here is a short video

• Before Changes

Screen.Recording.2026-02-04.150402.mp4

Sir as you can see here the right side table of content block is mixed of both docker compose steps and wsl steps.

• After Changes
  https://github.com/user-attachments/assets/7118615c-c8d5-46d2-bb01-2daf7a5a24d9

It is not alone in the Echo SQL Sample section, so where ever the issue is getting repeated i have modified them properly. It solved
the issue as you can see in the after changes video or screenshot.

[Achanandhi-M]

Hey @Srinu346, the changes look good. However, I noticed that no updates were made for the FastHTTP + Postgres setup. Could you please let me know why there are no changes there?

[Srinu346]

@Achanandhi-M sir, i already have a ongoing pr for FastHTTP + Postgres Setup so i avoided that in this pr.

[Achanandhi-M]

@Achanandhi-M sir, i already have a ongoing pr for FastHTTP + Postgres Setup so i avoided that in this pr.

In that case, please don’t create a PR and request a review until the changes are fully completed. Kindly raise the PR once everything has been addressed. @Srinu346

[Srinu346]

Ok Sir, i will wait until the previous pr is completely merged or closed, then will look into this.