Add mimetype to input parameter in schema

nextflow_schema.json

@@ -14,6 +14,7 @@
             "properties": {
                 "input": {
                     "type": "string",
+                    "mimetype": "text/tsv",
                     "description": "URI/path to an [SDRF](https://github.com/bigbio/proteomics-metadata-standard/tree/master/annotated-projects) file (.sdrf.tsv) **OR** [OpenMS-style experimental design](https://abibuilder.informatik.uni-tuebingen.de/archive/openms/Documentation/release/latest/html/classOpenMS_1_1ExperimentalDesign.html#details) with paths to spectra files (.tsv)",
                     "help_text": "Input is specified by using a path or URI to a PRIDE Sample to Data Relation Format file (SDRF), e.g. as part of a submitted and\nannotated PRIDE experiment (see [here](https://github.com/bigbio/proteomics-metadata-standard/tree/master/annotated-projects) for examples). Input files will be downloaded and cached from the URIs specified in the SDRF file.\nAn OpenMS-style experimental design will be generated based on the factor columns of the SDRF. The settings for the\nfollowing parameters will currently be overwritten by the ones specified in the SDRF:\n\n    * `fixed_mods`,\n    * `variable_mods`,\n    * `precursor_mass_tolerance`,\n    * `precursor_mass_tolerance_unit`,\n    * `fragment_mass_tolerance`,\n    * `fragment_mass_tolerance_unit`,\n    * `fragment_method`,\n    * `enzyme`\n  You can also specify an [OpenMS-style experimental design](https://abibuilder.informatik.uni-tuebingen.de/archive/openms/Documentation/release/latest/html/classOpenMS_1_1ExperimentalDesign.html#details) directly (.tsv ending). In this case, the aforementioned parameters have to be specified or defaults will be used.",
                     "fa_icon": "fas fa-file-csv"