Add terminal command for a Preview release (#4896)

* Add terminal command for a Preview release

Instructs to run `pwsh-terminal` if a PowerShell Preview release was installed.
See PowerShell/PowerShell/#10713

This could also be mentioned in a documentation block for a preview version for each supported OS (see [Snap instructions](https://github.com/MicrosoftDocs/PowerShell-Docs/blob/staging/reference/docs-conceptual/install/Installing-PowerShell-Core-on-Linux.md#snap-package) for example.)

* Fix broken hyperlink

Author: akamch

reference/docs-conceptual/install/Installing-PowerShell-Core-on-Linux.md

@@ -17,7 +17,7 @@ the Linux [`tar.gz` archive][tar], but you would need to set up the necessary de
 the OS in separate steps.
 
 All packages are available on our GitHub [releases][] page. After the package is installed, run
-`pwsh` from a terminal.
+`pwsh` from a terminal. Run `pwsh-preview` if you installed a [Preview release](#installing-preview-releases).
 
 [u16]: #ubuntu-1604
 [u1804]: #ubuntu-1804