Site pages do not have a meta description

[jbampton]

Meta descriptions may be included in search results to concisely summarize page content.

On the pages I checked the source was like:

<meta name="description" content="">

[tanmoyPaul12]

@jbampton please assign me this issue

[shivamyadavrgipt]

@jbampton i would like to fix this issue kindly assign me.

[jbampton]

@tanmoyPaul12 and @shivamyadavrgipt I don't have triage permissions on this repo.

cc @bproffitt

[tanmoyPaul12]

I’ve opened PR #623 to ensure meta description tags never render empty by
falling back to the site-wide description from pelicanconf.yaml.