add meta description for google lighthouse

[shibumi]

This adds a meta description to all websites for satisfying Google.
It also allows setting a "description" tag in every blog post for making it easier for Google to find these blog articles.

This is supposed to fix #119

[shibumi]

Hi can we get this merged? @Track3

[Track3]

Hi @shibumi
Sorry for the long wait, please resolve below and I will merge, thanks!

[Track3]

Instead of putting this in baseof.html, it's better placing this inside layouts/partials/structured-data.html.

As for code inside content attribute, I think we can refer to Hugo internal templates here:
https://github.com/gohugoio/hugo/blob/fc0f13b68451a09a6d6b4ce50c4217313b664176/tpl/tplimpl/embedded/templates/schema.html#L2

it covers more cases

{{ with .Description }}{{ . }}{{ else }}{{if .IsPage}}{{ .Summary }}{{ else }}{{ with .Site.Params.description }}{{ . }}{{ end }}{{ end }}{{ end -}}

[shibumi]

Hey, sorry for the late reply I do not work on my blog that often...

I checked your message and we are already impprting this schema.html template in our layouts/partials/structured-data.html:

{{- template "_internal/schema.html" . }}
{{- template "_internal/opengraph.html" . }}
{{- template "_internal/twitter_cards.html" . }}

Hence, I have no idea what you mean. The problem seem to be that the schema.html template from the _internall hugo library uses itemprop instead of name in the meta tag... and that's why it doesn't get recognized, because itemprop seem to be for social media stuff only.