Add espanso trigger for signature

Signed-off-by: Severin Kaderli <severin@kaderli.dev>

system/.config/espanso/default.yml

@@ -1,13 +1,4 @@
-# espanso configuration file
-
-# This is the default configuration file, change it as you like it
-# You can refer to the official documentation:
-# https://espanso.org/docs/
-
-# Matches are the substitution rules, when you type the "trigger" string
-# it gets replaced by the "replace" string.
 matches:
-  # Simple text replacement
   - trigger: ":mail"
     replace: "severin@kaderli.dev"
 
@@ -18,4 +9,11 @@ matches:
         type: date
         params: 
           format: "%F"
+
+  - trigger: ":sig"
+    replace: |
+      Freundliche Grüsse
+
+      Severin Kaderli
+      https://kaderli.dev
 ...