add c3c in github-linguist

[ghost]

Hi!

I was thinking of adding an issue on GitHub to identify .c3c files that are in the c3lang language.

What do you all think of this idea?

1. Example issue: add c3c in github-linguist

<!--

👋 If you have the time and know-how, send us a pull-request: everybody is welcome to contribute! 
Otherwise, fill out the following fields as best you can.

-->

## Language name
c3lang

## URL of example repository
https://github.com/c3lang/c3c

## URL of syntax highlighting grammar
http://www.c3-lang.org/

## Most popular extensions
`.c3`

<!--

List the extensions commonly used by this language.

-->

## Detected language
(None)

<!--

What language are files for this language being identified as, if any?

-->

2. main.c3 c3-lang/examples

fn void example_foreach(float[] values) 
{
    foreach (index, value : values) 
    {
        libc::printf("%d: %f\n", index, value);
    }
}

[data-man]

According to https://github.com/github/linguist/blob/master/CONTRIBUTING.md#adding-a-language

In most cases we prefer that each new file extension be in use in at least 200 unique :user/:repo repositories before supporting them in Linguist

But you can try! :)

[ghost]

Hi data-man. thank you for feedback, I'll try anyway.

[lerno]

And the suffix is .c3 😅

[ghost]

Hi lerno. thank you for feedback - I will make this fix.

[lerno]

And you need a js highlighter I think

[ghost]

Hi. Like this: highlightjs ? " Syntax highlighting for the Web" - highlightjs

[lerno]

Hmm... looking at it.. no, you need a textmate compatible grammar.

[lerno]

And the entry will end up looking something like

C3:
  type: programming
  color: "#555555"
  extensions:
  - ".c3"
  - ".c3t"
  tm_scope: source.c3

[lerno]

I mean the entry in languages.yml, not the grammar.