Show anchor links for each heading

[jamos-tay]

What is the purpose of this pull request? (put "X" next to an item, remove the rest)

• [X] New feature

Fixes #426

What is the rationale for this request?

Users may want to share a link to a specific heading with others.

What changes did you make? (Give an overview)

Allow users to automatically generate anchor links for each heading that direct the URL to that heading.

Provide some example code that this change will affect:

Users must include an anchors property in the frontmatter:

anchors: true

Functions similar to https://developers.timekit.io/v2/reference#section-root-endpoint-versions-and-protocol

• Hovering over a header shows an anchor icon
• Clicking on the icon links the URL to the header

Is there anything you'd like reviewers to focus on?

Should we make the behavior different from the example site (e.g. change the icon)?

[yamgent]

Users must include an anchors property in the frontmatter:

anchors: true

This seems kind of troublesome if there's a lot of such pages (if not all) in the website though (slightly similar to #389).

Was wondering whether we should add a default option in site.json, and explore a way to specify it for multiple pages at once...

[yamgent]

Should we make the behavior different from the example site (e.g. change the icon)?

Design in the example gif looks fine actually. 👍

[damithc]

This seems kind of troublesome if there's a lot of such pages (if not all) in the website though (slightly similar to #389).

Maybe no need for this to be configurable? i.e., we do it by default for all headings

[yamgent]

i.e., we do it by default for all headings

That sounds good too.

[jamos-tay]

Updated to solve merge conflict and automatically add anchors

[yamgent]

Tested the feature, works fine 👍.

[jamos-tay]

Updated

[yamgent]

One minor nit