When the page parser was rewritten in 0.51, this was interpreted literally, but commented out front matter is used in the wild to "hide it from GitHub", e.g:
```
<!--
+++
title = "hello"
+++
-->
```
Fixes#5478
An inline shortcode's name must end with `.inline`, all lowercase.
E.g.:
```bash
{{< time.inline >}}{{ now }}{{< /time.inline >}}
```
The above will print the current date and time.
Note that an inline shortcode's inner content is parsed and executed as a Go text template with the same context as a regular shortcode template.
This means that the current page can be accessed via `.Page.Title` etc. This also means that there are no concept of "nested inline shortcodes".
The same inline shortcode can be reused later in the same content file, with different params if needed, using the self-closing syntax:
```
{{< time.inline />}}
```
Fixes#4011