add solutions page to readme

Author: ablaom

Diff for: README.md

@@ -19,14 +19,15 @@ To **run demos and tutorials** presented in the workshop:
 
 Here are static views of the demos and tutorial notebooks:
 
-|Notebook |
-|:-------:|
-|[Mandelbrot set demo](notebooks/mandelbrot/notebook.ipynb) |
-[Julia's secret sauce](notebooks/secret_sauce/notebook.ipynb) |
-[Package composability](notebooks/pkg_composability/notebook.ipynb) |
-[01 - First_steps](notebooks/01_first_steps/notebook.unexecuted.ipynb) |
-[02 - DataFrames](notebooks/02_dataframes/notebook.ipynb) |
-[03 - Machine learning](notebooks/03_machine_learning/notebook.ipynb) |
+| Notebook                                                                          |
+|:---------------------------------------------------------------------------------:|
+| [Mandelbrot set demo](notebooks/mandelbrot/notebook.ipynb)                        |
+| [Julia's secret sauce](notebooks/secret_sauce/notebook.ipynb)                     |
+| [Package composability](notebooks/pkg_composability/notebook.ipynb)               |
+| [01 - First_steps](notebooks/01_first_steps/notebook.unexecuted.ipynb)            |
+| [02 - DataFrames](notebooks/02_dataframes/notebook.ipynb)                         |
+| [03 - Machine learning](notebooks/03_machine_learning/notebook.ipynb)             |
+| [99 - Solutions to exercises](notebooks/99_solutions_to_exercises/notebook.ipynb) |
 
 
 Some random resources for Julia newcomers: