Fixed sourcemap property - _config_dev.yml

[dellagustin]

When trying to run the command jekyll serve using _config_dev.yml,
it failed with the following error:

  Conversion error: Jekyll::Converters::Scss encountered an error while converting 'assets/css/atom.scss': undefined method `to_sym' for true:TrueClass Did you mean? to_s
------------------------------------------------
Jekyll 4.0.0   Please append `--trace` to the `serve` command
               for any additional information or backtrace.
------------------------------------------------

This happens because in _config_dev.yml sourcemap is set to true,
while the documentation at
https://github.com/jekyll/jekyll-sass-converter stated the allowed
values are never, always and development.

This PR fixes #93, and the issue was noticed when implementing #91.

[lenucksi]

LGTM based on the docs. Should only impact the dev environment if I read correctly?

[dellagustin]

I had to google LGTM 😄
yes, as the change is restricted to _config_dev.yml, it only affects development environment. I think the idea is to facilitate debugging of css related stuff that is generated from scss files.

If you look at https://github.com/InnerSourceCommons/innersourcecommons.org/blob/f84d08ed743f9935ef81ea7c3966d9d1e3c7ebcc/cibuild#L14 you will see that our build pipeline builds the rendered jekyll pages without explicitly providing any configuration, which means it takes into account only _config.yml, not changed by this PR.

[lenucksi]

I had to google LGTM smile
yes, as the change is restricted to _config_dev.yml, it only affects development environment. I think the idea is to facilitate debugging of css related stuff that is generated from scss files.

If you look at

https://github.com/InnerSourceCommons/innersourcecommons.org/blob/f84d08ed743f9935ef81ea7c3966d9d1e3c7ebcc/cibuild#L14
you will see that our build pipeline builds the rendered jekyll pages without explicitly providing any configuration, which means it takes into account only _config.yml, not changed by this PR.

Great, this should be merged then I'd say.