Replace images on playground steps

[tomasfabry]

I've also got some warnings:

  Line 131:  Using target="_blank" without rel="noopener noreferrer" is a security risk: see https://mathiasbynens.github.io/rel-noopener  react/jsx-no-target-blank
  Line 259:  Using target="_blank" without rel="noopener noreferrer" is a security risk: see https://mathiasbynens.github.io/rel-noopener  react/jsx-no-target-blank
  Line 274:  Using target="_blank" without rel="noopener noreferrer" is a security risk: see https://mathiasbynens.github.io/rel-noopener  react/jsx-no-target-blank
  Line 289:  Using target="_blank" without rel="noopener noreferrer" is a security risk: see https://mathiasbynens.github.io/rel-noopener  react/jsx-no-target-blank
  Line 304:  Using target="_blank" without rel="noopener noreferrer" is a security risk: see https://mathiasbynens.github.io/rel-noopener  react/jsx-no-target-blank
  Line 319:  Using target="_blank" without rel="noopener noreferrer" is a security risk: see https://mathiasbynens.github.io/rel-noopener  react/jsx-no-target-blank
  Line 334:   Using target="_blank" without rel="noopener noreferrer" is a security risk: see https://mathiasbynens.github.io/rel-noopener  react/jsx-no-target-blank
  Line 349:   Using target="_blank" without rel="noopener noreferrer" is a security risk: see https://mathiasbynens.github.io/rel-noopener  react/jsx-no-target-blank

I know it's not due to your changes, but maybe you can fix it if you will make some fixes related to the footer...

[lenhardt]

I also noticed that I need to add {' '} if I want to have space before or after anchor.

Sorry for the errors with "_blank" .. I will see how you fix it and will try not to introduce new errors like that!

[borisvida]

@tomasfabry Fixed, please, re-check :slightly_smiling_face:

@lenhardt About that _blank errors: you just need to add rel="noopener noreferrer" to the anchor. It's for security reasons, summed up here: https://mathiasbynens.github.io/rel-noopener/