Update readme

README.md

@@ -3,3 +3,53 @@
 
 A Cutter-Sanborn Four-Figure number generator
 
+## CLI installation
+Either install through npm:
+```
+npm install -g cuttersanborn
+```
+or download a standalone binary.
+
+## CLI usage help
+```
+options:
+    --help
+        shows the help
+
+    --file <filename>
+        A comma-separated list of names.
+        If <filename> is -, then input is read from stdin
+                    
+    --outputname
+        Shows the name in output
+
+    --name=lastname,firstname
+```
+
+### Example usage
+```
+$ cuttersanborn --name=Adams,John --name=Gabel,Linda --name="Andrews, Mary Helen"
+A214
+A216
+M393
+
+$ cuttersanborn --outputName --name=Adams,John --name=Gabel,Linda
+Adams,John A214
+Gabel,Linda A216
+
+```
+
+
+## Npm installation and usage
+Install on npm:
+```
+$npm install --save cuttersanborn
+```
+
+Then require/import in your code:
+```
+let generateCutter = await require("cuttersanborn")();
+let cutterNum      = await generateCutter(lastname, firstname);
+
+```
+Note: the functions return a promise.