feat: allow for disabling of active hash on scroll (#482)

[achendrick]

What kind of change does this PR introduce? (check at least one)

• Bugfix
• Feature
• Code style update
• Refactor
• Docs
• Build-related changes
• Other, please describe:

If changing the UI of default theme, please provide the before/after screenshot:

Does this PR introduce a breaking change? (check one)

• Yes
• No

If yes, please describe the impact and migration path for existing applications:

The PR fulfills these requirements:

• When resolving a specific issue, it's referenced in the PR's title (e.g. fix #xxx[,#xxx], where "xxx" is the issue number)

If adding a new feature, the PR's description includes:

• A convincing reason for adding this feature
• Related documents have been updated

To avoid wasting your time, it's best to open a feature request issue first and wait for approval before working on it.

Other information:

Auto setting the active hash based on the side bar links and page headers was having some non-ideal behaviors on my site. If you have headers that aren't in the side bar, or update the hash programmatically this feature can cause issues.

I introduced a simple config to disable the capability.

Please not I'm open to suggestions, I opted to check the config in an isolated area related to the logic, but it still maintains the scroll listener which may not be optimal or preferred.

[ulivz]

Thanks for your work!

I just renamed the disableActiveHash to activeHeaderLinks, made sure the script of active header links loaded on demand (b0c9e11), and updated document (affecd8)

[ulivz]

Close: #482