So you can do `process.env.HUGO_PUBLISHDIR` in your `postcss.config.js` to figure out where Hugo publishes
its files.
Note that the value will always be an absolute file path and will point to a directory on disk even when running `hugo server` in memory mode.
If you write to this folder from PostCSS when running the server, you could run the server with one of these flags:
```
hugo server --renderToDisk
hugo server --renderStaticToDisk
```
Fixes#10554
Note that we will now fail if `inlineImports` is enabled and we cannot resolve an import.
You can work around this by either:
* Use url imports or imports with media queries.
* Set `skipInlineImportsNotFound=true` in the options
Also get the argument order in the different NewFileError* funcs in line.
Fixes#9895
* Redo the server error template
* Always add the content file context if relevant
* Remove some now superflous error string matching
* Move the server error template to _server/error.html
* Add file context (with position) to codeblock render blocks
* Improve JS build errors
Fixes#9892Fixes#9891Fixes#9893
