Updating INSTALl docs re: SDL_gfx on macOS

docs/en/INSTALL.txt

@@ -656,6 +656,7 @@ Compiling and Installation
            * libsdl_mixer
            * libsdl_pango
            * libsdl_ttf
+           * libsdl_gfx
            * pkgconfig
            * zlib
          ... but you should install any package that is required by the

docs/en/html/INSTALL.html

@@ -842,6 +842,7 @@
               <li><code>libsdl_mixer</code></li>
               <li><code>libsdl_pango</code></li>
               <li><code>libsdl_ttf</code></li>
+              <li><code>libsdl_gfx</code></li>
               <li><code>pkgconfig</code></li>
               <li><code>zlib</code></li>
             </ul>

docs/es_ES.UTF-8/INSTALL.txt

@@ -656,6 +656,7 @@ Compiling and Installation
            * libsdl_mixer
            * libsdl_pango
            * libsdl_ttf
+           * libsdl_gfx
            * pkgconfig
            * zlib
          ... but you should install any package that is required by the

docs/es_ES.UTF-8/html/INSTALL.html

@@ -842,6 +842,7 @@
               <li><code>libsdl_mixer</code></li>
               <li><code>libsdl_pango</code></li>
               <li><code>libsdl_ttf</code></li>
+              <li><code>libsdl_gfx</code></li>
               <li><code>pkgconfig</code></li>
               <li><code>zlib</code></li>
             </ul>

docs/fr_FR.UTF-8/INSTALL.txt

@@ -682,6 +682,7 @@ Compilation et installation
            * libsdl_mixer
            * libsdl_pango
            * libsdl_ttf
+           * libsdl_gfx
            * pkgconfig
            * zlib
          ... mais vous devriez installer tout paquet requis par la dernière

docs/fr_FR.UTF-8/html/INSTALL.html

@@ -842,6 +842,7 @@
               <li><code>libsdl_mixer</code></li>
               <li><code>libsdl_pango</code></li>
               <li><code>libsdl_ttf</code></li>
+              <li><code>libsdl_gfx</code></li>
               <li><code>pkgconfig</code></li>
               <li><code>zlib</code></li>
             </ul>

docs/gl_ES.UTF-8/INSTALL.txt

@@ -666,6 +666,7 @@ Compiling and Installation
            * libsdl_mixer
            * libsdl_pango
            * libsdl_ttf
+           * libsdl_gfx
            * pkgconfig
            * zlib
          ... but you should install any package that is required by the

docs/gl_ES.UTF-8/html/INSTALL.html

@@ -842,6 +842,7 @@
               <li><code>libsdl_mixer</code></li>
               <li><code>libsdl_pango</code></li>
               <li><code>libsdl_ttf</code></li>
+              <li><code>libsdl_gfx</code></li>
               <li><code>pkgconfig</code></li>
               <li><code>zlib</code></li>
             </ul>

docs/ja_JP.UTF-8/INSTALL.txt

@@ -656,6 +656,7 @@ Compiling and Installation
            * libsdl_mixer
            * libsdl_pango
            * libsdl_ttf
+           * libsdl_gfx
            * pkgconfig
            * zlib
          ... but you should install any package that is required by the

docs/ja_JP.UTF-8/html/INSTALL.html

@@ -842,6 +842,7 @@
               <li><code>libsdl_mixer</code></li>
               <li><code>libsdl_pango</code></li>
               <li><code>libsdl_ttf</code></li>
+              <li><code>libsdl_gfx</code></li>
               <li><code>pkgconfig</code></li>
               <li><code>zlib</code></li>
             </ul>