(maint) Replace RawGit with raw.githack.com CDN

[PeterDaveHello]

RawGit is shutting down since October 2018, the content already been
serving will continue to be served until at least October of 2019, but
new content will not be served, the homepage https://rawgit.com/ says:

If you're currently using RawGit,
please stop using it as soon as you can.

raw.githack.com is another popular CDN service for repositories on
GitHub, and more, also including GitLab and Bitbucket, which provides
package maintainers more flexibility.

[pauby]

I think we should point to the Icon Guidelines here rather than specifying a specific service.

/cc @gep13 @ferventcoder

[ferventcoder]

I agree. @PeterDaveHello if you can point to this, that would allow us to pull this in.

[ferventcoder]

Just the one small thing - this looks great otherwise!

[PeterDaveHello]

I think it's in the guidelines already, isn't it? Just upload the example here to make it valid and as an useful reminder in the template, what do you think?

[bcurran3]

There are other CDNs that probably should be mentioned as well.
REF: chocolatey/choco-wiki#106

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution.
10 out of 12 committers have signed the CLA.

✅ gliptak
✅ gep13
✅ GankousKhan
✅ DdOtzen
✅ peteraritchie
✅ flcdrg
✅ jetersen
✅ skel35
✅ TheCakeIsNaOH
✅ FLeXyo
❌ Mauville
❌ PeterDaveHello
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[gep13]

LGTM!

[gep13]

@PeterDaveHello Thank you for taking the time to get this updated, really appreciate it! Since this is a simple documentation change, signing of the CLA is not required, so I am going to move forward to get this merged in.

[gep13]

@PeterDaveHello thanks again for your help here!

[PeterDaveHello]

Thanks @gep13 !