Setting multi-line variable only works in bash, so change setting GitHub release notes to bash

[stijnmoreels]

Describe the bug
Setting a multi-line variable only works in bash (actually a workaround, as it doesn't work in PowerShell).

To Reproduce
Steps to reproduce the behavior:

• Look at the GitHub releases pipeline, the multi-line value is not send to the GitHub release notes, only the first line.

Expected behavior
We should have a fully ready GitHub release with the titles automatically.

[fgheysels]

I believe this has something to do with the 'line-separator' character that you use ?
More info might be found here

[stijnmoreels]

I believe this has something to do with the 'line-separator' character that you use ? More info might be found here

It's a multi-line string, so not a command. We want to set such a multi-line string via a [vso.setvariable write to the console, but only the first line is there, so the value is already multi-line, it's just that the Azure DevOps in PowerShell does not seem to handle this correctly and in Bash it does handle it correctly.