fixed components; added playerapp example

examples/mediaplayer/playerapp.nim

@@ -0,0 +1,24 @@
+## Example app that shows how to write and embed a custom component.
+
+include karaxprelude
+import mediaplayer
+
+const url = "https://www.w3schools.com/html/mov_bbb.mp4"
+
+proc createDom(): VNode =
+  result = buildHtml(table):
+    tr:
+      td:
+        mplayer("vid1", url)
+      td:
+        mplayer("vid2", url)
+    tr:
+      td:
+        mplayer("vid3", url)
+      td:
+        mplayer("vid4", url)
+
+setRenderer createDom
+
+proc onload() {.exportc.} =
+  init()