Will be the home for the auto-generated semantic conventions constants.

Added instructions on how to update the PublicAPI files using the dotnet-format global tool.

To avoid having StyleCop warnings for the auto-generated files.

Now with the auto-generated header

Taking advantage of line breaks in long <remarks> and leveraging dotnet format tool to fix indentation afterwards.

For some reason dotnet tool -w does not remove it. Needed to use the -a for analysers but in a separate command.

Now that dotnet format is running. Also now public api files are updated automatically.

…emetry-dotnet into feat/autogen_semconv

dotnet-format is built-in in .NET 6. Also things changes and the template and script needed to change.

Before the dotnet-format tool used to auto-format comments that didn't start with a space. In the new version this is not happening anymore and I couldn't find out why. For now, on `remarks` an empty space is added always.

# Conflicts:
#	OpenTelemetry.proj
#	OpenTelemetry.sln

Used the new config in the code generator to make things easier in regards to whitespace/newlines in the template.
Now the Jinja expressions do not leave whitespaces when the code file is generated. If newlines are required, they
have to be present in the template file.

Escape filter seems to do the job to escape invalid chars inside a xml comment block

And other minor improvements.