docs: Remove texture compression formats that don\'t exist

  </li>

  <li><strong>S3TC (DXT<em>n</em>/DXTC)</strong> - S3 texture compression (S3TC) has several

format variations (DXT1 to DXT5) and is less widely available. The format supports RGB textures with

4-bit alpha or 8-bit alpha channels. This format may be represented by several OpenGL extension

names, for example:

4-bit alpha or 8-bit alpha channels. These formats are represented by the following OpenGL extension

name:

    <ul>

      <li>{@code GL_OES_texture_compression_S3TC}</li>

      <li>{@code GL_EXT_texture_compression_s3tc}</li>

    </ul>

    Some devices only support the DXT1 format variation; this limited support is represented by the

following OpenGL extension name:

    <ul>

      <li>{@code GL_EXT_texture_compression_dxt1}</li>

      <li>{@code GL_EXT_texture_compression_dxt3}</li>

      <li>{@code GL_EXT_texture_compression_dxt5}</li>

    </ul>

  </li>

  <li><strong>3DC</strong> - 3DC texture compression (3DC) is a less widely available format that