feat: add Defibrillators challenge and TypeScript solution

challenges/defibrillators/README.md

@@ -0,0 +1,66 @@
+# Defibrillators
+
+Created by [@Divlo](https://github.com/Divlo) on 18 February 2021.
+
+## Instructions
+
+### Goals
+
+The city of Montpellier has equipped its streets with defibrillators to help save victims of cardiac arrests. The data corresponding to the position of all defibrillators is available online.
+
+Based on the data we provide in the tests, write a program that will allow users to find the defibrillator nearest to their location using their mobile phone.
+
+### Rules
+
+The input data you require for your program is provided in text format.
+
+This data is comprised of lines, each of which represents a defibrillator. Each defibrillator is represented by the following fields:
+
+- A number identifying the defibrillator
+- Name
+- Address
+- Contact Phone number
+- Longitude (degrees)
+- Latitude (degrees)
+
+**Note 1**: These fields are separated by a semicolon (;).
+
+**Note 2**: Beware: the decimal numbers use the comma (,) as decimal separator. Remember to turn the comma (,) into dot (.) if necessary in order to use the data in your program.
+
+### Distance
+
+The distance `d` between two points `A` and `B` will be calculated using the following formula:
+
+![Distance Formula](./distance-formula.png)
+
+**Note**: Note: In this formula, the latitudes and longitudes are expressed in **radians**. 6371 corresponds to the radius of the earth in km.
+
+**Note 2**: To convert radian to degrees : (π /180)
+
+The program will display the name of the defibrillator located the closest to the user’s position. This position is given as input to the program.
+
+The `solution` function takes 3 parameters :
+
+- `userLongitude` (in degrees)
+- `userLatitude` (in degrees)
+- `defibrillators` array of strings with the following format : `1;Maison de la Prevention Sante;6 rue Maguelone 340000 Montpellier;;3,87952263361082;43,6071285339217`
+
+### Example
+
+```js
+solution('3,879483', '43,608177', [
+  '1;Maison de la Prevention Sante;6 rue Maguelone 340000 Montpellier;;3,87952263361082;43,6071285339217',
+  '2;Hotel de Ville;1 place Georges Freche 34267 Montpellier;;3,89652239197876;43,5987299452849',
+  '3;Zoo de Lunaret;50 avenue Agropolis 34090 Mtp;;3,87388031141133;43,6395872778854'
+])
+```
+
+It should returns `"Maison de la Prevention Sante"`.
+
+## Source
+
+[CodinGame - Defibrillators](https://www.codingame.com/training/easy/defibrillators)
+
+## Examples
+
+See the `input-output.json` file for examples of input/output.