examples: add a template example, update the regex examples (#8829)

examples/regex/readme.md

@@ -0,0 +1,8 @@
+# regex
+
+There are 2 ways to do regex:
+a) using the native module called `regex`
+b) using an exteranl module called `pcre`, which wraps the C library pcre.
+NB: you need to first do: `v install pcre`, for the `pcre` module to work.
+
+You can find examples of both in this directory.