Added og meta tags.

Signed-off-by: Pavel Kirilin <s3riussan@gmail.com>

.gitattributes

@@ -1 +1,2 @@
 **/*.csv filter=lfs diff=lfs merge=lfs -text
+**/*.png filter=lfs diff=lfs merge=lfs -text

zangramru/static/index.html

@@ -4,6 +4,14 @@
     <meta charset="UTF-8">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     <title>Занграммы</title>
+    <meta property="og:title" content="Занграммы">
+    <meta property="og:description" content="Игра со словами — находи слова на сетке">
+    <meta property="og:image" content="/preview.png">
+    <meta property="og:type" content="website">
+    <meta name="twitter:card" content="summary_large_image">
+    <meta name="twitter:title" content="Занграммы">
+    <meta name="twitter:description" content="Игра со словами — находи слова на сетке">
+    <meta name="twitter:image" content="/preview.png">
     <style>
         * { margin: 0; padding: 0; box-sizing: border-box; }
         body {
@@ -40,13 +48,15 @@
             font-size: 2rem;
             font-weight: bold;
             color: #fff;
-            min-height: 3rem;
+            height: 3rem;
             margin-bottom: 0.5rem;
             letter-spacing: 0.3em;
             cursor: pointer;
             padding: 0.5rem;
             border-radius: 8px;
             transition: background 0.2s;
+            display: inline-block;
+            text-align: center;
         }
         #wordDisplay:hover { background: rgba(255,255,255,0.05); }
         #message {