Add Go Template and differentiate from Smarty

[trewallier]

Description

Add Go template as a new language.
This PR is intended to solve #7639 and #6196 so that Helm chart repositories are classified correctly.
Note that Go template use braces similarly to Jinja {{ }} and the file extension might not differentiate template languages in general. So this PR focus only on Smarty - Go template differences as they usually share the same extension in Helm charts.

Rationale for added extensions:

• .gohtml: IntelliJ IDEA has association with this extension. (link to source)
• .html.tmpl: GitHub search verifies that is widely used. Mentioned in a StackOverflow answer and also default in a Prettier plugin.
• .gotmpl, .tmpl: Default extensions of Go template files the Go language server (gopls) (link to documentation). Also the VS Code Go Plugin use this default (link to docs).
• .tpl: Convention used in Helm charts as stated by the Helm documentation ("Conventionally, Helm charts put [...] templates inside of a partials file, usually _helpers.tpl")

Since none of the extensions are defined by the Go template documentation, and none of the supporting tools stick to one particular default, I left the list in alphabetical order in the languages.yml config.

Checklist:

• I am adding a new language.

  • The extension of the new language is used in hundreds of repositories on GitHub.com.
    • Search results for each extension:
      • _helpers.tpl https://github.com/search?type=code&q=NOT+is%3Afork+path%3A**%2F_helpers.tpl+%7B%7B-
      • .gohtml https://github.com/search?type=code&q=NOT+is%3Afork+path%3A*.gohtml
      • .gotmpl https://github.com/search?type=code&q=NOT+is%3Afork+path%3A*.gotmpl
      • .html.tmpl https://github.com/search?type=code&q=NOT+is%3Afork+path%3A*.html.tmpl
      • .tmpl https://github.com/search?type=code&q=NOT+is%3Afork+path%3A*.tmpl+%7B%7B-
      • .tpl https://github.com/search?type=code&q=NOT+is%3Afork+path%3A*.tpl+%7B%7B-
  • I have included a real-world usage sample for all extensions added in this PR:
    • Sample source(s):
      • _helpers.tpl source
      • base.tpl source
      • batch.gohtml source
      • _templates.gotmpl source
      • crd.tmpl source
      • letter.tmpl source
      • prettier.html.tmpl source
    • Sample license(s):
      • _helpers.tpl CC BY 4.0
      • base.tpl MIT
      • batch.gohtml MIT
      • _templates.gotmpl Apache License 2.0
      • crd.tmpl Apache License 2.0
      • letter.tmpl BSD-3-Clause
      • prettier.html.tmpl MIT License
  • I have included a syntax highlighting grammar: https://github.com/jinliming2/vscode-go-template
  • I have added a color
    • Hex value: #00ADD8
    • Rationale: Used same color as all other Go languages
  • I have updated the heuristics to distinguish my language from others using the same extension.

• I am fixing a misclassified language

  • I have included a new sample for the misclassified language:
    • Sample source(s):
      • header.tpl source
      • index.tpl source
    • Sample license(s):
      • header.tpl LGPL LICENSE
      • index.tpl LGPL LICENSE
  • I have included a change to the heuristics to distinguish my language from others using the same extension.

• I am updating a grammar submodule

[lildude]

Along with the inline comments, we also need a sample and supporting search string for all extensions you are adding support for. Any one extension that doesn't meet usage requirements will block this PR from being merged until it does so it's best to start small and add support later as usage grows. Users can use an override in the mean time.

[lildude]

See the comment at the top of this file. The first extension should be the language's primary extension. Your comments and the fact you've not provided a sample or supporting search result suggests this is not the primary extension for the language.

[trewallier]

Thanks for the reminder, added my reason to the PR description why I did not choose default. If you suggest one particular extension as default based on the description I can update the PR happily.

[lildude]

You're guessing and haven't run the tests 😉

This needs a supporting grammar. Linguist doesn't currently have a grammar that provides this scope so this either needs to be set to text (which kinda defeats the point in differentiating when you're not going to get any syntax highlighting) or you need to add a grammar.

I notice you conveniently removed that section of the template too 😉

[trewallier]

Sure I missed the test, and tried to fix them in f0ffa72. Still I get some repo reference errors on my fork. Do you have any suggestion where should I start with errors like this? Or is it just happening because on a fork?
Rugged::OdbError: object not found - no match for id (7dbcffcf982e766fc711e633322de848f2b60ba5)

Added supporting grammar. Feel free to suggest anything else which might fit better.

Also sorry for the sloppy PR description, I was not expecting such a quick review, and wanted to save my progress.

[lildude]

Or is it just happening because on a fork?
Rugged::OdbError: object not found - no match for id (7dbcffc)

This normally happens if you've only included the main branch when forking. We have tests that rely on objects in the test/attributes brach.

[trewallier]

Thanks for the quick review, tried to fix every issue from the first commit, and added more info to the PR description.

Regarding the extensions I researched the topic from every aspect I could, and included search strings. Still if you feel I should remove some, just let me know. For me it looked like every search string has at least 10k results, but I may interpret the search result incorrecty.