New {file} formatter

[psprint]

Description

I'm refreshing the old pr #421 taking into account @vladdoster's objections about the number of colors used to highlight (now there is 1 color for extensions instead of 2). Also, a new feature – highlighting of the version number (like e.g. v1.5). Furthermore, I'm submitting a branch that's on top of #550 , after merging this PR the commits will disappear from this PR.

Related Issue(s)

#421

Motivation and Context

The flexibility behind +zinit-message allows for sophisticated highlighters. Here the {file} style gets a private function-highlighter to color file extensions and version automatically with a distinct color.

Usage examples

Default theme:

Blue theme:

Gold theme:

How Has This Been Tested?

Via the above invocations of +zinit-message interactively.

Types of changes

• Breaking change (fix or feature that would cause existing functionality to change)
• Bug fix (non-breaking change which fixes an issue)
• Documentation change
• New feature (non-breaking change which adds functionality)

Checklist:

• All new and existing tests passed.
• I have added tests to cover my changes.
• I have updated the documentation accordingly.

[psprint]

@vladdoster @pschmitt @alichtman ping :)

[psprint]

@vladdoster: ping, The version coloring is cool and should be merged