[TASK] Markdown syntax by live example link on edit page

Also, edit description field is extracted as a partial.

Resources/Private/Partials/EditDescription.html

+<div class="form-group">
+	<label for="description" class="col-sm-2 control-label">Description</label>
+
+	<div class="col-sm-10">
+		<f:form.textarea property="description" id="description" class="form-control min-height200" />
+		<div>
+			Markdown syntax by live example:
+			<a target="_blank" href="https://markdown-it.github.io">https://markdown-it.github.io</a>
+		</div>
+	</div>
+</div>

Resources/Private/Templates/Tsref/EditProperty.html

@@ -48,13 +48,7 @@
 						</div>
 					</div>
 
-					<div class="form-group">
-						<label for="description" class="col-sm-2 control-label">Description</label>
-
-						<div class="col-sm-10">
-							<f:form.textarea property="description" id="description" class="form-control min-height200" />
-						</div>
-					</div>
+					<f:render partial="EditDescription" arguments="{_all}" />
 
 					<div class="actions">
 						<nav class="form-navigation">

Resources/Private/Templates/Tsref/EditType.html

@@ -45,13 +45,7 @@
 						</div>
 					</div>
 
-					<div class="form-group">
-						<label for="description" class="col-sm-2 control-label">Description</label>
-
-						<div class="col-sm-10">
-							<f:form.textarea property="description" id="description" class="form-control min-height200" />
-						</div>
-					</div>
+					<f:render partial="EditDescription" arguments="{_all}" />
 
 					<div class="actions">
 						<nav class="form-navigation">