docs: add keywords

Ipxxiao · Ipxxiao · commit 818c74b19446 · 2020-08-10T09:55:59.000+08:00
diff --git a/package.json b/package.json
@@ -15,6 +15,8 @@
         "calculation",
         "floating-point",
         "decimal",
+        "lightweight",
+        "high performance",
         "add",
         "addition",
         "subtract",
