Extract example from the README to a runnable location.

examples/simple.nim

@@ -0,0 +1,22 @@
+import vcard
+
+# Reading in an existing vcard
+let vcards = parseVCard3File("jack.vcf")
+assert vcards.len == 1
+let vcAllen = vcards[0]
+
+assert vcAllen.email.len == 2
+assert vcAllen.email[0].value == "allen@fosters.test"
+assert vcAllen.n.given[0] == "Jack"
+
+# Creating a new VCard
+var vcSusan: VCard3
+vcSusan.add(@[
+  newVC3_N(given = @["Susan"], family = @["Foster"]),
+  newVC3_Email(value = "susan@fosters.test", emailType = @["PREF",
+  $etInternet]),
+  newVC3_Tel(
+    value = "+1 (555) 444-3889",
+    telType = @[$ttHome, $ttCell, $ttVoice, $ttMsg])
+])
+writeFile("susan.vcf", $vcSusan)