Update readme and update some test files to be better examples

test/valid-verify-multi-line.hcl

@@ -1,10 +1,10 @@
 check_interval = "1s"
 
 monitor "Shell" {
-  shell_command = <<EOF
-echo 'Some string with stuff';
-echo "<angle brackets>";
-exit 1
+  shell_command = <<-EOF
+    echo 'Some string with stuff'
+    echo "<angle brackets>"
+    exit 1
   EOF
   alert_down = ["log_shell"]
   alert_after =  1
@@ -13,7 +13,7 @@ exit 1
 
 alert "log_shell" {
   shell_command = <<EOF
-echo 'Some string with stuff'
-echo '<angle brackets>'
+    echo 'Some string with stuff'
+    echo '<angle brackets>'
 EOF
 }