feat(sample): use chat commands in WalkCommands sample

Merge pull request #14 from Rutherther/packets-span

Rewrite packets string enumerator to use spans, add Injector for .NET 5+

feat: update samples to use UnmanagedCallersOnly entrypoint

chore: update packages to netstandard 2.1

chore: fix line endings

Merge branch 'walk-command-handler' into 'main'

Walk command handler

Closes #4

See merge request Rutherther/nos-smooth!2

feat: add sample for walk command