README.md convert example needs to be updated

[riyenas0925]

Hello
First of all, thank you for making a good tool.

• java-tools supports conversion to json and yaml, but it is not shown in README.md
• In the spdx format converters section of the readme.md file, we checked that the example was different from the actual one.
  AS-IS : java -jar spdx-tools-jar-with-dependencies.jar TagToRDF Examples/SPDXTagExample.tag TagToRDF.rdf
  TO-BE : java -jar spdx-tools-jar-with-dependencies.jar Convert Examples/SPDXTagExample.tag TagToRDF.rdf

reference

Usage: java -jar spdx-tools-jar-with-dependencies.jar <function> <parameters>
function                 parameter                         example
-------------------------------------------------------------------------------------------------------------------
Convert         inputFile outputFile [fromType] [toType]   Examples/SPDXTagExample.tag TagToSpreadsheet.xls
SPDXViewer      inputFile                                  TestFiles/SPDXRdfExample.rdf
Verify          inputFile [type]                           TestFiles/SPDXRdfExample.rdf
CompareDocs     output.xlsx doc1 doc2 ... docN
GenerateVerificationCode sourceDirectory
Version
MatchingStandardLicenses licenseTextFile

can I contribute by revising README.md and sending pr?

Thank you!

[goneall]

@riyenas0925 - Good catch on the documentation.

Yes - please go ahead and submit a PR.

Thanks!

[riyenas0925]

Dear @goneall
pr requested 😄
please let me know if there is anything I need to change