feat: output-type markdown

[christiangda]

• Extend the output format to a markdown table, allowing to show results in the Github action's workflow summary

--> --output-type= output type [values: default,markdown,cloc-xml,sloccount,json] (default: default)

I started to use this go program recently on my Github Action Workflows, and I did a bash hack to convert the --output-type=default output to Markdown table

My hack is:

      - name: Lines of code
        run: |
          echo "## Line of code" >> $GITHUB_STEP_SUMMARY

          go install github.com/hhatto/gocloc/cmd/gocloc@latest
          gocloc --not-match-d=vendor,bin,build,dist,docs,examples,scripts,testdata,tests,tools . \
          | tail -n +2 | sed -e '$ d' | sed 's/^/|/' | sed 's/ \{1,\}/  \|  /g' | sed 's/$/\|/' | tac |sed '2d'| tac | sed 's/---\{5,20\}/--|--/g' \
          | tee -a $GITHUB_STEP_SUMMARY

To show it as:

As a hack, this is fine, but the columns were not aligned as expected, so I decided to make this pull request to do that natively in the code, so now this is the result:

I hope this will be util and accepted