Merge branch '5-readme'

README.md

@@ -1,2 +1,72 @@
 # property-utils
 Utilities for programming that involves physical properties
+
+---
+**Documentation:** https://maxcode123.github.io/property-utils/  
+**Source code:** https://github.com/Maxcode123/property-utils  
+**PyPI:** https://pypi.org/project/property-utils/  
+
+---
+
+## What is property-utils?
+property-utils is a python library that aims at making programming with physical properties easier. It was created to be used by scientists and engineers with little programming experience.
+
+**What is provided by property-utils?**
+
+### Unit arithmetics
+You can divide and multiply units to create new units. For example you can create velocity units by dividing length units with time units.
+
+### Unit conversions
+You can easily convert a property from one unit to another by calling a method.
+
+### Property arithmetics
+You can add, subtract, divide and multiply properties to create new properties. For example, you can create a density property by dividing a mass property with a volume property.
+
+## Installation
+```
+pip install property-utils
+```
+
+## Quick usage
+
+A simple example:
+
+```py
+import math
+
+from property_utils.properties import p
+from property_utils.units import (
+    BTU,
+    FOOT,
+    RANKINE,
+    HOUR,
+    CENTI_METER,
+    METER,
+    KELVIN,
+    KILO_WATT,
+)
+
+tube_radius = p(12, CENTI_METER)
+tube_length = p(2.3, METER)
+heat_exchange_area = 2 * math.pi * tube_radius * tube_length
+
+heat_transfer_coeff = p(150, BTU / RANKINE / FOOT**2 / HOUR)
+
+cold_in = p(273, KELVIN)
+cold_out = p(300, KELVIN)
+hot_in = p(520, KELVIN)
+hot_out = p(472, KELVIN)
+diff_in = hot_in - cold_in
+diff_out = hot_out - cold_out
+temperature_diff = (diff_in - diff_out) / math.log((diff_in / diff_out).value)
+
+heat_duty = (heat_transfer_coeff * heat_exchange_area * temperature_diff).to_unit(KILO_WATT)
+
+print(heat_duty)
+```
+
+Result:
+
+```
+306.1224518046951 kW
+```