added KRL config and sample

lib/linguist/languages.yml

@@ -680,6 +680,11 @@ Kotlin:
   - .ktm
   - .kts
 
+KRL:
+  type: programming
+  color: "#f5c800"
+  primary_extension: .krl
+
 LLVM:
   primary_extension: .ll
 

samples/KRL/helloworld.krl

@@ -0,0 +1,15 @@
+ruleset sample {
+  meta {
+    name "Hello World"
+    description <<
+Hello world
+>>
+    author "Phil Windley"
+  }
+
+  // just one rule
+  rule hello {
+    select when web pageview
+    notify("Hello world!", "Just a note to say hello");
+  }
+}