Suggestions to SDRF v1.1.0

I really like the addition of subdomain-specific templates! Feedback on what I think would be still great to have in SDRF 1.1.0:

* Allow multiple —templates separated by , e.g. immunopeptidomics,dda-ms-proteomics to validate against
* Add functionality that generates an header-only tsv file based on the `--template` flag that the user can fill
* Data-dependent acquisition (DDA) Template addition request (optional columns):
* comment[precursor mass tolerance]
* comment[fragment mass tolerance]
* comment[digest mass range]
* comment[prec charge]

@ypriverol @timosachsenberg

Start by tracing the existing --template entry point and template validation flow. Determine how multiple templates, header-only TSV generation, and the requested optional DDA columns fit the current SDRF templates; done means each requested behavior is supported and covered by the project's existing checks.

Written by the indexing model from the issue text.