added functions

functions/findstr.fish

@@ -0,0 +1,10 @@
+function findstr
+    if test (count $argv) -lt 1
+        echo "Usage: findstr <search-string>"
+        return 1
+    end
+
+    set query $argv[1]
+
+    find . -type f -exec grep -Hn "$query" {} \;
+end