fix: README table (#571)

small fix to display correct table border.

Before the fix (see bottom of "Mask" cell):

![screen-2](https://github.com/vercel/satori/assets/1787206/cb8cb86a-02b0-4015-b3c8-6ea3c78b33fe)

After the fix:

![screen-1](https://github.com/vercel/satori/assets/1787206/03b1a7b4-0e77-4e5b-8d71-c834f179fa0a)

Author: tehuel

README.md

@@ -264,7 +264,7 @@ Satori uses the same Flexbox [layout engine](https://yogalayout.com) as React Na
 <td><a href="https://og-playground.vercel.app/?share=5VPBbtQwEP2VkRFakNKSshxQBBwoXDhwaEFc9uLYk6xbx2PZk-6G1Up8DR_GlzDOkgr13FtPGb_xvPf8ojkoQxZVo95Zd7cJAJknj-8Ph1IDbNH1W25gdVHXz1fVCdw5y9sHmHU5ej0J2nncL2ipP7mEhh0F6Rny4xCWbtTWutA3cFH_Q1ptbvtEY7CX5CnJxLOu6-7ZKPC1-4kNrF_P0PG4CR9KsZh_aP9_X60nc7tQAXgX8NLrIQrbPTjo1LvwkZhpkJF1HferU69IAcxiAN8zWmgnyDQgUAe8RdhR8naVwQsFZgZDQ9TBYa7gK-75_CYDBt16zDDRCExgEmpG6EbvzzLLy-EHtqBj9M7oElguGjKLocQ0q3iZEPIr1Iahk_kxFQUdLLjA2CcZlKuRdpiEGK7GzGetLn6_6Dt9bZKLLOIkz-8l0DSzdjrPtO3ovM3nc6KvJNJHyHa1ho368-s3vDBihQb5fVayEa-BX27UE093-apKUZxNqeag5v1Szdu6rtRpAVXzphwstmOvmk77jJXCgW7ctymW7eXdfBKesiSfhxatajiNeKwU61ZubNF7mmNUx78">Example</a></td>
 </tr>
 
-<tr><td rowspan="7">Mask</td></tr>
+<tr><td rowspan="5">Mask</td></tr>
 <tr><td><code>maskImage</code></td><td><code>linear-gradient(...)</code>, <code>radial-gradient(...)</code>, <code>url(...)</code></td><td><a href="https://og-playground.vercel.app/?share=pZJfb9MwFMW_imVp2ZDS5s_I1kULSMAkhgRoYlJf-uLYN8ltHTvYDm2o-t2xuxXBXvcQXed3rONj37unXAugJb0V-GulCLFuklDt92FNSAfYdq4k51manp3HT3CLwnUvmEA7SDZ52kjYnWhYf0ID3KFWXuNajr06qUxiq-4d9DZIoByYk7QercNm-qg9VOH8_-XG8x_4G0pymf-Dls9pr9L0mdaMb1qjRyW8x2jkRefcYMskwZ61YOejCrFtN-e6T4ZOOz3LinyRL65v3ubZdTZrari8KkQmbhh_jzuJdWXqWTbP51n0s1oUUdNX66GNuNFD5TP6MkXbKsvTNOK2sqatI9yhqGD60vHPHxq2fMDv67v022NbNA9vTjfqmd3ch0w-p2ECmZy1oXrLC46GSyDMkSI9C19MajlCTJxhPj8zftNfoyXUG3RfX21HkuTYBf-whhhowGMOBBXpXC_DWYfDSr1bqdvET46vNKZ6CH22tNzT44zQMrxDTJ-miJahL1RAPba0bJi0EFPo9RofpyGMoNse_7xRaOZdX4OgpTMjHGLqWO13dCCl3mojBT38AQ">Example</a></td></tr>
 <tr><td><code>maskPosition</code></td><td>Supported</td><td><a href="https://og-playground.vercel.app/?share=pVJda9swFP0rQlC3Ayf-6NKmpt5gW2Ed7KOskJe8yNK1fRNZ8iR5iRfy3yelCayFPfXBvtK5h3uP7j07yrUAWtBbgb-XihDrRgnlbhfOhLSATesKcp6l6dl5_ARuULj2BSbQ9pKNHq0lbE9oOH9CA9yhVj7HtRw6dcoyiY26d9DZkALlwJxSq8E6rMeP2oMq9H-erj3-E_9AQS7zf6DFUe1Vmh7RivF1Y_SghK8xGHnROtfbIkmwYw3Y6aCCbNtOue6SvtVOT7JZPs_n1zdv8-w6m9QVXF7NRCZuGH-PW4lVaapJNs2nWfSrnM-iuitXfRNxo_vSa_RhjDZllqdpxG1pTVNFuEVRwvil5Z8_1GzxgN9Xd-m3x2ZWP7w5vahjdn0fNHmdhglkctKE6EtecDRcAmGOzNKz8MWkkgPExBnm9TPjSc8K_dAWjxP3O-q35PA_MRZQrdF9fX1DkiSHRfnZG2KgBo9zIKhI6zr5stl_RAXafr9U75bqNvEe9JHGVPeBammxowe30SJMNKZPfqRF2DAVUA0NLWomLcQUOr3Cx7EPZnabw80XCra46yoQtHBmgH1MHas8owUp9UYbKej-Lw">Example</a></td></tr>
 <tr><td><code>maskSize</code></td><td>Support two-value size i.e. `10px 20%`</td><td><a href="https://og-playground.vercel.app/?share=pVLfb9MwEP5XLEvLhpQ2P0a3LlpAAiYxJEATk_rSF8e-JNc6drAd2lD1f8duV8H6yoN19ved7j7ffTvKtQBa0HuBv5aKEOtGCeVuF-6EtIBN6wpymaXpxWV8BDcoXHuGCbS9ZKNHawnbExrun9AAd6iV57iWQ6dOLJPYqEcHnQ0UKAfmRK0G67AeP2oPqtD_NV17_Af-hoJc5_9Aixe1N2n6glaMrxujByV8jcHIq9a53hZJgh1rwE4HFWTbdsp1l_StdnqSzfJ5Pr-9e5tnt9mkruD6ZiYyccf4e9xKrEpTTbJpPs2in-V8FtVdueqbiBvdl16jD2O0KbM8TSNuS2uaKsItihLGLy3__KFmiyf8vnpIvz03s_rpzelHHbPrx6DJ6zRMIJOTJkRf8oqj4RIIc2SWXoQTk0oOEBNnmNfPjE96Veg4Gr-ffkvyvztaQLVG9_X_O5EkOWzID90QAzV4nANBRVrXyfNm52oCv98v1buluk-863ykMdV98IilxY4e_EWLMMOYHh1Ii7BTKqAaGlrUTFqIKXR6hc9jH-zrNoeXLxSM8NBVIGjhzAD7mDpW-YwWpNQbbaSg-z8">Example</a></td></tr>