add boilerplate title and intro #264

doc/implementation-notes.md

@@ -1,3 +1,11 @@
+# Wave Interference - implementation notes
+
+This document contains notes related to the implementation of Wave Interference. The audience for this document is software developers who are familiar with JavaScript and PhET simulation development, as described in [PhET Development Overview](http://bit.ly/phet-html5-development-overview).
+
+Before reading this document, see [model.md](https://github.com/phetsims/equality-explorer/blob/master/doc/model.md), which provides a high-level description of the simulation model.
+
+## Overview
+
 The Wave Interference simulation depicts waves on a 2 dimensional surface and the interference patterns they create.  
 The first 3 screens show a 2D lattice and time-based wave propagation, while the fourth screen shows the interference 
 pattern from a slit with a given 2d shape, which is instantly updated.  
@@ -8,7 +16,7 @@ Other sim-specific query parameters are described in wave-interference/js/common
 There are no dynamically created/destroyed user interface components or model elements in the simulation, so the
 simulation doesn't require dispose calls.
 
-# The first three Screens: Waves, Interference, Slits
+## The first three Screens: Waves, Interference, Slits
 
 The first three screens are mainly implemented in js/common.  
 
@@ -43,7 +51,7 @@ correct.
 
 The following values can also be reported by running with`?log`.
 
-## Water
+### Water
 | Value | Frequency (Hz) | Wavelength (cm) |
 | :--- | ---: | ---: |
 | min | 0.25 | 7.4 |
@@ -52,13 +60,13 @@ The following values can also be reported by running with`?log`.
 Wave speed measured at 7.1E-2/1.43 = 5cm/sec.  In https://github.com/phetsims/wave-interference/issues/43 we decided this
 is a reasonable wave speed for a wave pool, even though it doesn't match wave speeds for, say, oceanic waves.
 
-## Sound
+### Sound
 | Value | Frequency (Hz) | Wavelength (cm) |
 | :--- | ---: | ---: |
 | min | 220 | 156 |
 | max | 440 | 78 |
 
-## Light
+### Light
 | Color | Frequency (THz) | Wavelength (nm) | 
 | :--- | ---: | ---: | 
 | Red (VisibleColor min) | 384.35 | 780.00 | 
@@ -69,13 +77,13 @@ which is about 4% off of the true speed of light.  Measuring the colored wavefro
 Since the distance and wave propagation speeds are independent of frequency, measurements for different colors will
 give the same speed of light.  See also WavesScreenModel usage of `timeScaleFactor` for how the model is calibrated.
 
-## Slits Screen
+### Slits Screen
 Here is a schematic for the two-slit dimensions:
 ![schematic for the two-slit dimensions](images/slitDimensions.jpg?raw=true "Two-Slit Dimensions")
 
 By using `?dev`, you can show the IdealInterferenceOverlay, which depicts d sin(θ) = mλ (theoretical maxima) and d sin(θ) = (m+1/2)λ (theoretical minima).
 See https://github.com/phetsims/wave-interference/issues/74
 
-# The Final Screen: Diffraction
+## The Final Screen: Diffraction
 In the fourth screen, we use a Fast Fourier Transform (FFT) in order to compute the diffraction pattern, see
 https://en.wikipedia.org/wiki/Diffraction