Merge pull request #1 from dnparadice/mbp19

- updated readme, added more info in examples

ReadMe.md

@@ -1,6 +1,6 @@
 ![PyCalc](media/PyCalc-ListsAndPlot.jpg)
 
-## Hello and welcome to PyCalc, the RPN ~~calculator~~ ~~IDE~~ progam that loves Python
+## Hello and welcome to PyCalc, the RPN ~~calculator~~ ~~IDE~~ program that loves Python
 
 This project is an experiment to see what happens when you take a Python interpreter, and put an RPN calculator style
 UI wrapper around it. 
@@ -97,6 +97,32 @@ imported Python module's functions can be called directly from the stack to oper
 functions from the NumPy library so you can call them directly from the stack by typing the function name and then 
 pressing enter.
 
+#### Saving and Restoring Sessions
+
+The calculator has the ability to save and restore sessions. By default the calculator will save it's state on exit
+and load the state on start. The state is saved in the directory where the calculator is run from as 
+"last_state_autosave.pycalc". The save and restore state includes the stack, history, variables and calculator settings.
+
+Saving 
+1) With some values on the stack and/or in variables press: 'ctrl+s' or navigate to the file menu and select 'save'
+2) Select a location and name for the session file and press 'save'
+
+Restoring 
+
+3) With the calculator open press: 'ctrl+o' or navigate to the file menu and select 'open'
+4) In the file dialog select the session file and press 'open'
+
+
+#### User Options
+
+You can set some options in the calculator by navigating to the 'options' menu. The options are:
+- 'Save State on Exit' -- Turn this off and the calculator will initialize on launch each time.
+- 'Edit float format string' -- This will open a dialog where you can set the format string for floating point numbers, see: https://fstring.help/cheat/
+- 'Edit int format string' -- This will open a dialog where you can set the format string for integers, see: https://fstring.help/cheat/
+- 'Edit plot format string' -- This will open a dialog where you can set the format string for plots, for valid strings, see Parameters: **fmt** here: https://matplotlib.org/stable/api/_as_gen/matplotlib.pyplot.plot.html
+
+
+
 
 
 #### Notes on Usage