Added MIME Types

[RehanSaeed]

Added the following MIME types which I have found to be missing:

.json - application/json (This one is pretty unbelievable)
.ttc - application/x-font-ttf
.webp - image/webp
.appcache - text/cache-manifest
.manifest - text/cache-manifest

Also the following MIME types need updating:

.ttf should be application/x-font-ttf and not application/octet-stream

[dnfclas]

Hi @RehanSaeed, I'm your friendly neighborhood .NET Foundation Pull Request Bot (You can call me DNFBOT). Thanks for your contribution!

This seems like a small (but important) contribution, so no Contribution License Agreement is required at this point. Real humans will now evaluate your PR.

TTYL, DNFBOT;

[Tratcher]

What are your references for these definitions?

[RehanSaeed]

Officially recognised MIME types:

• .json - application/json
• .appcache - text/cache-manifest and here
• .manifest - text/cache-manifest and here

There is no official standard MIME type for ttf, ttc and webp. However, these are common enough and I've gathered up whatever sources I can:

• .ttf is already included in the list but as application/octet-stream. However this causes a common warning to show in Chrome. See StackOverflow and Google Chrome. The solution is to use application/x-font-ttf where the x- signifies that this is non-standard. Some people use application/font-ttf instead however.
• ttc is a true type font collection and has similar problems in Chrome. Unfortunately I can't find an authoritative source for this one and I haven't written a comment about this one in my list. However HTML 5 Boilerplate has it listed as application/x-font-ttf.
• .webp - image/webp and HTML 5 Boilerplate. The first link is the official Google docs. It's worth noting that Chrome and Opera already support this format and other browsers can be supported using a shim. WebM is already in the list also.

Interestingly, HTML 5 Boilerplate has the following comment about the ttf and ttc font MIME types:

    # Browsers usually ignore the font media types and simply sniff
    # the bytes to figure out the font type.
    # https://mimesniff.spec.whatwg.org/#matching-a-font-type-pattern
    #
    # However, Blink and WebKit based browsers will show a warning
    # in the console if the following font types are served with any
    # other media types.

It's amazing to me how much of the web is not standardised and people have just somehow settled on 'what works'.

[Tratcher]

@blowdart do you care about any of these?

[blowdart]

Nope, you can merge at will.