added mastercard.svg file (#874)

* added mastercard.svg file

* edited code for mastercard.svg

* Compressed mastercard.svg to 322 Bytes

CHECK.html

@@ -229,6 +229,7 @@ <h1>
 <tr><td>Malt</td><td><img src="https://edent.github.io/SuperTinyIcons/images/svg/malt.svg" width="100" /></td><td><img src="https://edent.github.io/SuperTinyIcons/images/svg/malt.svg" width="100" style="border-radius: 50%;"></td><td><img src="https://edent.github.io/SuperTinyIcons/images/reference/malt.svg" width="100"></td></tr>
 <tr><td>Manjaro</td><td><img src="https://edent.github.io/SuperTinyIcons/images/svg/manjaro.svg" width="100" /></td><td><img src="https://edent.github.io/SuperTinyIcons/images/svg/manjaro.svg" width="100" style="border-radius: 50%;"></td><td><img src="https://edent.github.io/SuperTinyIcons/images/reference/manjaro.svg" width="100"></td><td><a href="https://manjaro.org/img/logo.svg">https://manjaro.org/img/logo.svg</a></td></tr>
 <tr><td>Markdown</td><td><img src="https://edent.github.io/SuperTinyIcons/images/svg/markdown.svg" width="100" /></td><td><img src="https://edent.github.io/SuperTinyIcons/images/svg/markdown.svg" width="100" style="border-radius: 50%;"></td><td><img src="https://edent.github.io/SuperTinyIcons/images/reference/markdown.png" width="100"></td><td><a href="https://www.markdownguide.org/">https://www.markdownguide.org/</a></td></tr>
+<tr><td>mastercard</td><td><img src="https://edent.github.io/SuperTinyIcons/images/svg/mastercard.svg" width="100" /></td><td><img src="https://edent.github.io/SuperTinyIcons/images/svg/mastercard.svg" width="100" style="border-radius: 50%;"></td><td><img src="https://edent.github.io/SuperTinyIcons/images/reference/mastercard.png" width="100"></td><td><a href="https://www.mastercard.com/global/en.html">https://www.mastercard.com/global/en.html</a></td></tr>
 <tr><td>Mastodon</td><td><img src="https://edent.github.io/SuperTinyIcons/images/svg/mastodon.svg" width="100" /></td><td><img src="https://edent.github.io/SuperTinyIcons/images/svg/mastodon.svg" width="100" style="border-radius: 50%;"></td><td><img src="https://edent.github.io/SuperTinyIcons/images/reference/mastodon.svg" width="100"></td><td><a href="https://github.com/tootsuite/joinmastodon/blob/master/public/press-kit.zip">https://github.com/tootsuite/joinmastodon/blob/master/public/press-kit.zip</a></td></tr>
 <tr><td>matrix</td><td><img src="https://edent.github.io/SuperTinyIcons/images/svg/matrix.svg" width="100" /></td><td><img src="https://edent.github.io/SuperTinyIcons/images/svg/matrix.svg" width="100" style="border-radius: 50%;"></td><td><img src="https://edent.github.io/SuperTinyIcons/images/reference/matrix.svg" width="100"></td></tr>
 <tr><td>Mattermost</td><td><img src="https://edent.github.io/SuperTinyIcons/images/svg/mattermost.svg" width="100" /></td><td><img src="https://edent.github.io/SuperTinyIcons/images/svg/mattermost.svg" width="100" style="border-radius: 50%;"></td><td><img src="https://edent.github.io/SuperTinyIcons/images/reference/mattermost.png" width="100"></td><td><a href="https://www.mattermost.org/brand-guidelines/">https://www.mattermost.org/brand-guidelines/</a></td></tr>