Merge pull request #18 from orual/natb/calc

add calculator

Author: espeon

Cargo.lock

@@ -92,6 +92,9 @@ html2md = "0.2"
 scraper = "0.22"
 regex = "1.11.1"
 
+# Calculator tool dependencies
+fend-core = "1.5.7"
+
 # Local crates (to be added later)
 # pattern-nd = { path = "../pattern-nd", optional = true }