update readme

README.md

@@ -1,2 +1,35 @@
 # ptrace.nim
-ptrace wrapper for Nim
+ptrace wrapper and helpers for Nim
+
+
+## Installation
+
+    $ nimble install ptrace
+
+## Example
+
+```nim
+import ptrace/ptrace
+
+var child: Pid;
+var syscallNum: clong;
+
+child = fork()
+if child == 0:
+  traceMe()
+  discard execl("/bin/ls", "ls")
+else:
+  var a: cint
+  wait(nil)
+
+  var regs = getRegs(child)
+  echo "Syscall number: ", regs.orig_rax
+  if errno != 0:
+    echo errno, " ", strerror(errno)
+
+  syscallNum = peekUser(child, SYSCALL_NUM)
+  if errno != 0:
+    echo errno, " ", strerror(errno)
+  echo "The child made a system call: ", syscallNum
+  cont(child, nil)
+```