Address Sass global function deprecation warnings

[chaoscommencer]

Deprecation warnings:

• Deprecation Warning [global-builtin]: Global built-in functions are deprecated and will be removed in Dart Sass 3.0.0.
  Use color.adjust instead.
• Deprecation Warning [color-functions]: lighten() is deprecated.
• Deprecation Warning [color-functions]: darken() is deprecated.

NOTE: 'color.adjust' is used instead to preserve pre-existing behavior

NOTE: This version of the change requires changes 519c8ee - 2074190 from the pull request addressing use of @import

[ashmaroli]

Hello @chaoscommencer, thank you for submitting this pull request. However, this is a non-backwards compatible change and therefore not within the scope of the 2.x series.

However, this change isn't acceptable on the master branch as well (as of now) since users on the legacy Ruby Sass (via Jekyll 3.x and jekyll-remote-theme plugin) won't be able to use these changes.

I won't be closing this right away but keeping it in limbo for the distant future.

[chaoscommencer]

No problem; I have notifications on in case you would like assistance with this later. I think I saw a similar pull request open for the master branch already. This one of course only applies to the 2.5-stable branch. Have a good one!

[UlyssesZh]

@ashmaroli I thought we've moved on about the problems of breaking changes on the master branch because they are already there as you mentioned at #815 (comment).

[ashmaroli]

@UlyssesZh, I used the clause may migrate in the comment you have linked to.

However, my concern with going forwards with changes in this branch is not just about breaking changes. That would be acceptable given that master is already at v5.0.0.dev. My concern is about users on Jekyll 3.x consuming this theme via jekyll-remote-theme not being able to continue consuming further changes to master because jekyll-3.x cannot use jekyll-sass-converter-3.x.

If its still not clear, follow the steps below at your end:

• clone this repository.
• check out this pull request branch. (accessible at refs/pull/849/head)
• Edit Gemfile to use jekyll ~> 3.9.
• Build / serve the site to see if the result is acceptable.
• Edit Gemfile to include jekyll-sass-converter ~> 3.0.
• Build / serve the site.