Copy getting started info to separate file

docs/start.md

@@ -0,0 +1,59 @@
+# Getting Started
+
+## Installation
+PySR uses both Julia and Python, so you need to have both installed.
+
+Install Julia - see [downloads](https://julialang.org/downloads/), and
+then instructions for [mac](https://julialang.org/downloads/platform/#macos)
+and [linux](https://julialang.org/downloads/platform/#linux_and_freebsd).
+(Don't use the `conda-forge` version; it doesn't seem to work properly.)
+Then, at the command line,
+install the `Optim` and `SpecialFunctions` packages via:
+
+```bash
+julia -e 'import Pkg; Pkg.add("Optim"); Pkg.add("SpecialFunctions")'
+```
+
+For python, you need to have Python 3, numpy, sympy, and pandas installed.
+
+You can install this package from PyPI with:
+
+```bash
+pip install pysr
+```
+
+## Quickstart
+
+```python
+import numpy as np
+from pysr import pysr
+
+# Dataset
+X = 2*np.random.randn(100, 5)
+y = 2*np.cos(X[:, 3]) + X[:, 0]**2 - 2
+
+# Learn equations
+equations = pysr(X, y, niterations=5,
+            binary_operators=["plus", "mult"],
+            unary_operators=["cos", "exp", "sin"])
+
+...
+
+print(equations)
+```
+
+which gives:
+
+```
+   Complexity       MSE                                                Equation
+0           5  1.947431                          plus(-1.7420927, mult(x0, x0))
+1           8  0.486858           plus(-1.8710494, plus(cos(x3), mult(x0, x0)))
+2          11  0.000000  plus(plus(mult(x0, x0), cos(x3)), plus(-2.0, cos(x3)))
+```
+
+The newest version of PySR also returns three additional columns:
+
+- `score` - a metric akin to Occam's razor; you should use this to help select the "true" equation.
+- `sympy_format` - sympy equation.
+- `lambda_format` - a lambda function for that equation, that you can pass values through.
+

pydoc-markdown.yml

@@ -36,12 +36,15 @@ renderer:
       name: index
       source: README.md
       directory: '..'
-    - title: API Documentation
-      contents:
-        - pysr.sr.pysr
-    - title: Operators
-      name: operators
-      source: docs/operators.md
+    - title: Getting started
+      name: getting-started
+      source: docs/start.md
     - title: Options
       name: options
       source: docs/options.md
+    - title: Operators
+      name: operators
+      source: docs/operators.md
+    - title: API Documentation
+      contents:
+        - pysr.sr.pysr