updated gitignore and readme

.gitignore

@@ -1 +1,2 @@
 doc/*
+*.gem

README.md

@@ -4,6 +4,40 @@ Ruby/ProgressBar is a text progress bar library for Ruby.
 
 It can indicate progress with percentage, a progress bar, and estimated remaining time.
 
+## Examples
+
+Basic functionality:
+
+    % irb --simple-prompt -r progressbar
+    >> pbar = ProgressBar.new("test", 100)
+    => (ProgressBar: 0/100)
+    >> 100.times {sleep(0.1); pbar.inc}; pbar.finish
+    test:          100% |oooooooooooooooooooooooooooooooooooooooo| Time: 00:00:10
+    => nil
+
+Set position directly:
+
+    >> pbar = ProgressBar.new("test", 100)
+    => (ProgressBar: 0/100)
+    >> (1..100).each{|x| sleep(0.1); pbar.set(x)}; pbar.finish
+    test:           67% |oooooooooooooooooooooooooo              | ETA:  00:00:03
+
+Block mode:
+
+    >> ProgressBar.block('test',100) do |pbar|
+    >>   100.times { sleep(0.1); pbar.inc }
+    >> end
+
+Even simpler:
+
+    >> (1..100).to_a.each_with_progressbar('test') do
+    >>   sleep 0.1
+    >> end
+
+## Installation
+
+    gem install ruby-progressbar
+
 ## Limitations
 
 Since the progress is calculated by the proportion to the