Maciej Sawicki d6b2282582 templates: Fix series detection in opengraph
When inside front matter you specified series with spaces,
then the opengraph template wouldn't detect other articles,
because in `.Site.Taxonomies.series` they are stored by
urlized key.

Example:

```yaml
series:
    - My Series
```

```gohtml
{{/* in a template */}}
{{- $series := index .Site.Taxonomies.series$name }}

{{/* was resolved to */}}
{{- $series := index {'my-series': ...} "MySeries" }}
```

(cherry picked from commit d2d493ab5d6a054001a8448ea0de2949dac4b30e)
2020-12-16 18:07:59 +05:30
..