Adds emoji font and function to test emoji support

In my quest to learn more about terminals, I added a function to output ten
emojis. Technically this tests the same thing as test_unicode.

Unfortunately I couldn't get `st` to output any colored emojis. This is a bit of
a buzzkill for my grand plans to create a terminal-based chat client that
supports emojis.

configs/shared/zsh/functions.zsh

@@ -303,6 +303,16 @@ test_unicode() {
   echo -e '\u26FD \u26FE \u26FF'
 }
 
+test_emojis() {
+  # Outputs a few emojis to see if your terminal supports colored or
+  # monochromatic emojis.
+  for n in {0..9}
+  do
+    echo -e -n "\U1F60$n"
+  done
+  echo # newline to clean output
+}
+
 path() {
   # Pretty-print the $PATH variable
   echo "$PATH" | tr : '\n'