Allow customizing favicon about neuron HOT 4 CLOSED

Before we merge this master, I'm thinking if we should also allow specifying the other icon type -- touch icons (apple-touch-icon and apple-touch-icon-precomposed).

Ref:

• https://wordpress.org/support/topic/fav-icon-and-apple-touch-icon/
• https://webmasters.stackexchange.com/questions/2010/favicon-icon-shortcut-icon-apple-touch-icon-are-there-any-others
• https://mathiasbynens.be/notes/touch-icons

from neuron.

Okay, here's what I propose.

There are unmanageable number of favicon combinations, however using svg favicons will simplify the configuration greatly (browser support ongoing).

I suggest basically the following HTML:

<link rel="icon" sizes="any" type="image/svg+xml" href="/static/favicon.svg">
<link rel="alternate icon" href="/static/favicon.png">
<link rel="alternate icon" href="/static/favicon.ico">
<!-- See https://medium.com/swlh/are-you-using-svg-favicons-yet-a-guide-for-modern-browsers-836a6aace3df -->
<link rel="apple-touch-icon" href="/static/apple-touch-icon.png">

(If we really want, we can expand this list in future)

Generate each of these only if the corresponding icon file exists in the zettelkasten ./static directory. If no favicons exist, use the default neuron logo as favicon.

Convention over configuration. neuron.dhall need not be touched.

Read Are you using SVG favicons yet?

from neuron.

Icons can also be specified via the manifest.webmanifest file which can likewise be detected and injected as:

<link rel="manifest" href="static/manifest.webmanifest">

from neuron.

Moved to #256

from neuron.