improved main page

Author: simongravelle

docs/index.html

@@ -33,7 +33,7 @@ <h2>
                     <section class="tiles">
                         <article class="style1">
                             <span class="image">
-                                <img src="avatars/level1/bulk-solution/bulk-solution-gromacs.png" alt="gromacs tutorial logo" />
+                                <img src="avatars/level1/bulk-solution/bulk-solution-gromacs.png" alt="Ionic solution, simple GROMACS tutorial" />
                             </span>
                             <a href="sphinx/build/html/tutorials/tutorial1/bulk-solution.html">
                                 <div class="content">
@@ -45,7 +45,7 @@ <h2>
                         </article>
                         <article class="style1">
                             <span class="image">
-                                <img src="avatars/level1/protein-in-electrolyte/protein-in-electrolyte.png" alt="gromacs tutorial logo" />
+                                <img src="avatars/level1/protein-in-electrolyte/protein-in-electrolyte.png" alt="Protein in water, simple GROMACS tutorial" />
                             </span>
                             <a href="sphinx/build/html/tutorials/tutorial2/protein-in-electrolyte.html">
                                 <div class="content">
@@ -57,7 +57,7 @@ <h2>
                         </article>
                         <article class="style1">
                             <span class="image">
-                                <img src="avatars/level2/stretching-a-polymer/stretching-polymer-gromacs.png" alt="gromacs tutorial logo" />
+                                <img src="avatars/level2/stretching-a-polymer/stretching-polymer-gromacs.png" alt="Stretching a polymer in water, advanced GROMACS tutorial" />
                             </span>
                             <a href="sphinx/build/html/tutorials/tutorial3/stretching-a-polymer.html">
                                 <div class="content">
@@ -79,7 +79,7 @@ <h2>
                                 <li>
                                     <a target="_blank" href="https://github.com/gromacstutorials"
                                     class="icon brands fa-github fa-3x">
-                                        <span class="label">Github</span>
+                                        <span class="label">GitHub</span>
                                     </a>
                                 </li>
                                 <li>