Add GHA tag, name, & version to the release body template object

[jmuzina]

What's changed

Adds support for template replacement of the following action input variables in .github/release-drafter.yml:

Variable	Description
$INPUT_TAG	input.tag from GHA workflow
$INPUT_NAME	input.name from GHA workflow
$INPUT_VERSION	input.version from GHA workflow

Reason / Use case

I am using the input.version action input to pass in a specific version for the drafted release without using $NEXT_PATCH_VERSION, $NEXT_MINOR_VERSION, $NEXT_MAJOR_VERSION, $RESOLVED_VERSION etc. I want to also be able to use this inputted value in the body of the release draft, but noticed it is not supported in any of the template variable sections here, and not passed into template() in generateReleaseInfo() (link).

[jmuzina]

Update.... is $INPUT_VERSION already supported? I think I just found it here:

release-drafter/lib/versions.js

Line 140 in 77cfd85

$INPUT_VERSION: splitSemVersion(input, 'inputVersion'),

but it is not documented in README so it was hard to tell that this behavior was supported :)

[jetersen]

You can use both $RESOLVED_VERSION or $INPUT_VERSION
$RESOLVED_VERSION can be overwritten by $INPUT_VERSION but also can also be resolved by the semver increment operation chosen (major, minor, patch)