add handler, html templates, Makefile and migrations

templates/post_create.html

@@ -0,0 +1,20 @@
+
+            {{define "header"}}
+            <h5>Create a new post in</h5>
+            <h1 class="mb-0">{{.Thread.Title}}</h1>
+            {{end}}
+
+                {{define "content"}}
+                <form action=/threads/{{.Thread.ID}} method="POST">
+                    <div class="form-group">
+                        <label>Title</label>
+                        <input name="title" type="text" class="form-control" placeholder="Give your post a great title">
+                    </div>
+                    <div class="form-group">
+                        <label>Text</label>
+                        <textarea name="content" class="form-control" rows="3"
+                            placeholder="Tell people about your thoughts"></textarea>
+                    </div>
+                    <button type="submit" class="btn btn-primary">Submit Post</button>
+                </form>
+                {{end}}