Improve README

README.md

@@ -1,16 +1,23 @@
-# pw - Password generator
+# pw -- Password generator
 
 ## Quick start
 
 ### Build
 
+#### Dependencies
+
+First build & install
+[libscnumerics](https://git.bobpolis.com/bob/libscnumerics).
+
+Then:
+
 `make`
 
 ### Install
 
 `sudo make install`
 
-(or, on OpenBSD):
+Or, on OpenBSD:
 
 `doas gmake install`
 
@@ -20,14 +27,23 @@
 
 Generate password using default settings.
 
+## Examples
+
+Generate a password with at least one lower case letter, one upper case letter,
+and one digit, with a length of 20 characters:
+
+`pw -l 1 -u 1 -d 1 -c 20`
+
+or, more compact:
+
+`pw -l1 -u1 -d1 -c20`
+
+Generate a password containing symbols from a given set:
+
+`pw -S '+-=@'`
+
 ## Documentation
 
-See the man page, when installed:
+Full documentation is in the man page:
 
 `man pw`
-
-## Dependencies
-
-First build & install
-[libscnumerics](https://git.bobpolis.com/bob/libscnumerics).
-