cleanup README

* Update build instructions
* Remove outdated documentation

The example in the README was no longer working. So we remove the
example altogether, no documentation is better than outdated
documentation which will just be misleading and/or frustrating for
users.

README.md

@@ -37,76 +37,11 @@ If you have `make` and `conda` available, a common workflow could be:
 ```
 $ make conda-env                        # setup conda environment
 $ conda activate numba-rvsdg            # activate it
-$ make                                  # "build" the project
-$ make test                             # run all tests
-$ make docs                             # build the docs
-$ open docs/build/html/index.html       # view the docs (OSX)
+$ make                                  # lint, build and test the project
 ```
 
 Feel free to look at the `makefile` for low-level commands.
 
-
-## overview
-
-The following files are included in this repository:
-
-```
-numba_rvsdg
-├── __init__.py
-├── core
-│   ├── datastructures
-│   │   ├── basic_block.py  # BasicBlock implementation
-│   │   ├── scfg.py         # SCFG implementation, maps names to blocks
-│   │   ├── byte_flow.py    # ByteFlow implementation, SCFG + bytecode
-│   │   ├── flow_info.py    # Converts program to ByteFlow
-│   ├── transformations.py  # Algorithms
-│   └── utils.py            # Miscellaneous utilities
-├── networkx_vendored
-│   └── scc.py              # Strongly Connected Componets (loop detection)
-├── rendering
-│   └── rendering.py        # Graphivz based rendering of SCFGs
-├── tests
-│   ├── simulator.py        # Simulator utility for running SCFGs
-│   ├── test_byteflow.py    # Testung ByteFlow and others
-│   ├── test_fig3.py        # Testing fig. 3 from Bahman2015
-│   ├── test_fig4.py        # Testing fig. 4 from Bahman2015
-│   ├── test_simulate.py    # Simulator based testing
-│   └── test_transforms.py  # Testing graph transformations
-└── utils
-```
-
-## example
-
-The following will process the given example function and display the four
-different stages. "initial" is the unprocessed bytecode as produced by
-cpython. "closed" is simply the closed variant of the initial CFG. "loop
-restructuring" is the loop-restructured version and "branch-restructured" is
-the final form which includes closing, loop-restructuring and
-branch-restructuring.
-
-
-```python
-# Example: for loop with branch and early exit
-
-from numba_rvsdg.rendering.rendering import render_func
-
-def foo(n):
-    c = 0
-    for i in range(n):
-        c += 1
-        if i == 100:
-            break
-    return c
-
-render_func(foo)
-
-```
-
-![initial](docs/images/initial.png "initial")
-![closed](docs/images/closed.png "closed")
-![loop-restructured](docs/images/loop_restructured.png "loop-restructured")
-![branch-restructured](docs/images/branch_restructured.png "branch-restructured")
-
 ## references
 
 * `Reismann2020` -- https://arxiv.org/pdf/1912.05036.pdf -- Describes the concept of RVSDGs