README for 3rd task

courses/ruby/ex03-wallet/README.md

@@ -1,3 +1,64 @@
-# TODO: Structure and finalize me please !
+The goal of these exercises is to help you understand classes and methods, both how they work and how they can improve you code readability and flexability instead using just functions.
+
+# Exercise structure
+Unit test example:
+```ruby
+class WalletTest < Minitest::Test
+  def test_wallet_starts_at_zero
+    #skip
+    wallet = Wallet.new
+    assert_equal 0, wallet.cents
+    assert_equal 0, wallet.dollars
+  end
+
+  def test_wallet_starts_at_non_zero
+    #skip
+    wallet = Wallet.new(:penny, :nickel)
+    assert_equal 6, wallet.cents
+    assert_equal 0.06, wallet.dollars
+  end
+end
+```
+You should implement a simple wallet Class, which may contain 5 types of currency: penny, nickel, dime, quarter, dollar.
+Your wallet should store two fields: counts of cents and dollars. This fields must be readable.
+Also you should create next methods: 
+1)Initializing new wallet with specified nominals (for one for each type) or just empty wallet if no arguments passed \
+2) Adding any coin or dollar to wallet ( "<<" method - takes one argument - name of currency ) \
+3) Getting one coin or one dollar from wallet if respective nominal exists in wallet. ( "take" method - takes some number of currencies) 
+
+# Running the test files
+Unit tests are implemented with Minitest. If you did not check doc yet it's time to do it now.
+
+# Running test suite:
+```console
+ruby wallet_test.rb
+```
+Expected output:
+```console
+Run options: --seed 8431
+
+# Running:
+
+..........
+
+Finished in 0.000935s, 10699.5929 runs/s, 34238.6972 assertions/s.
+10 runs, 32 assertions, 0 failures, 0 errors, 0 skips
+```
+
+# Running rubocop:
+```console
+rubocop wallet_test.rb
+```
+
+Expected output:
+```console
+Inspecting 1 file
+.
+
+1 file inspected, no offenses detected
+```
+
+# Bonus
+Fix all rubocop offences and submit patch without solution. If there is something to improve in .rubocop.yml you are welcome!
+
 
-Use ex01 README.md as a template.