✨ feat(mark): add dark/light marks for solidity (#19)

- Added 'solidity-dark.svg' mark.
- Added 'solidity-light.svg' mark.

Author: hwhsu1231

README.md

@@ -132,6 +132,18 @@
       <td><a href="https://setuptools.pypa.io/en/stable/artwork.html">Link</a></td>
       <td>By <a href="https://github.com/abravalheri">Anderson Bravalheri</a>, licensed under <a href="https://opensource.org/license/mit/">MIT</a>.</td>
     </tr>
+    <tr>
+      <td><code>mark/solidity-dark.svg</code></td>
+      <td><img src="mark/solidity-dark.svg" alt="solidity-dark" width="100"/></td>
+      <td><a href="https://github.com/argotorg/solidity/blob/11be2f4881d1644f15b026d1022388f06a034a34/docs/_static/img/logo.svg">Link</a></td>
+      <td>By <a href="https://www.soliditylang.org/">The Solidity Authors</a>, licensed under <a href="https://creativecommons.org/licenses/by/4.0/">CC BY 4.0</a>.</td>
+    </tr>
+    <tr>
+      <td><code>mark/solidity-light.svg</code></td>
+      <td><img src="mark/solidity-light.svg" alt="solidity-light" width="100"/></td>
+      <td><a href="https://github.com/argotorg/solidity/blob/11be2f4881d1644f15b026d1022388f06a034a34/docs/_static/img/logo-dark.svg">Link</a></td>
+      <td>By <a href="https://www.soliditylang.org/">The Solidity Authors</a>, licensed under <a href="https://creativecommons.org/licenses/by/4.0/">CC BY 4.0</a>.</td>
+    </tr>
     <tr>
       <td><code>mark/sphinx-dark.svg</code></td>
       <td><img src="mark/sphinx-dark.svg" alt="sphinx-dark" width="100"/></td>