Added: LDM Notes for April 29, 2019

[agocke]

https://github.com/dotnet/csharplang/blob/master/meetings/2019/LDM-2019-04-29.md

[DaZombieKiller]

There's a minor typo (albeit one that had me scratching my head for a brief moment, not realizing it was just a typo) near the beginning of the document: if the base implementation that was present at compile time is removed at rune time. rune time should be run time.

[MgSam]

@DaZombieKiller Are you sure that's a typo? I was always convinced the C# compiler had a little bit of magic in it. :)