Options page modernization

[wheelercj]

Currently, Stardown's settings page is very simple. I would like to keep it easy to use and lightweight, but there are many ways it could be improved.

For example, the options page could let users directly:

• report bugs
• request a feature
• donate

All without navigating to GitHub or another website.

Custom template

When the user chooses the setting "When creating markdown of a selection, use a custom template", an input field for a custom template appears. There are specific variables available for use in the custom template, but what they are is not made as clear to the user as it could be. If the user enters a variable that does not exist, an error message appears, but if they aren't using a variable that does exist, there's no easy way for them to find out about it. Currently, all available variables are already present in the default value for the custom template. There are many ways we could improve this. Maybe a link to new documentation, autocomplete suggestions, a list of available variables, and/or something else?

[wheelercj]

In the future, settings for customizing markdown formatting will probably be added, such as:

• code block style: fenced or indented. If fenced, backticks or tildes.
• heading style: atx or setext
• bold style: ** or __
• italic style: * or _
• indent with 4 spaces or a \t
• inline links or reference links
• whether to convert superscripts like y^[1] to y[1] or y^[1]^, and subscripts like H₂O to H2O or H~2~O (the latter of each use the rarely supported markdown syntax explained in Extended Syntax | Markdown Guide)
• whether to align tables

[wheelercj]

@chizuo about grouping the settings that Stardown currently has, here's what I'm thinking:

• General
  • Output markup language: ___
  • Copying links for all tabs copies from tabs in ___
  • Include a text fragment when creating a link for a selection (sometimes impacts performance)
  • Show warning notifications (warnings indicate partial success)
  • Show success notifications
• Readability
  • Omit navigation elements from source format selections
  • Omit footer elements from source format selections
  • Omit hidden elements from source format selections
• Markdown
  • When creating markdown of a selection, ___
  • Markdown bullet point symbol: ___
  • Replace square brackets in markdown link text with ___
  • Optimize markdown of YouTube videos for ___
• JSON
  • Empty table cells are converted to ___ in JSON
  • Save JSON output to ___