Merge branch 'feature/improve-readibility-of-ipynb-diffs' into 'master'

spec/lib/gitlab/diff/rendered/notebook/diff_file_spec.rb

vendor/gems/ipynbdiff/lib/output_transformer.rb

vendor/gems/ipynbdiff/lib/transformer.rb

vendor/gems/ipynbdiff/spec/testdata/error_output/expected.md

...ipynbdiff/spec/testdata/error_output/expected_symbols.txt

vendor/gems/ipynbdiff/spec/testdata/hide_images/expected.md

.../ipynbdiff/spec/testdata/hide_images/expected_symbols.txt

...ms/ipynbdiff/spec/testdata/ignore_html_output/expected.md

...iff/spec/testdata/ignore_html_output/expected_symbols.txt

vendor/gems/ipynbdiff/spec/testdata/latex_output/expected.md

...ipynbdiff/spec/testdata/latex_output/expected_symbols.txt

.../ipynbdiff/spec/testdata/multiline_png_output/expected.md

...f/spec/testdata/multiline_png_output/expected_symbols.txt

...ems/ipynbdiff/spec/testdata/percent_decorator/expected.md

...diff/spec/testdata/percent_decorator/expected_symbols.txt

vendor/gems/ipynbdiff/spec/testdata/stream_text/expected.md

.../ipynbdiff/spec/testdata/stream_text/expected_symbols.txt

vendor/gems/ipynbdiff/spec/testdata/svg/expected.md

vendor/gems/ipynbdiff/spec/testdata/svg/expected_symbols.txt

vendor/gems/ipynbdiff/spec/testdata/text_output/expected.md