Add better doc on readme

README.md

@@ -5,7 +5,12 @@ This project is affiliated with the [Maison du logiciel libre (ML<sup>2</sup>)](
 **Table of Contents**  *generated with [DocToc](https://github.com/thlorenz/doctoc)*
 
 - [course-activity-planner](#course-activity-planner)
-    - [Setup](#setup)
+  - [How to use](#how-to-use)
+    - [General principle](#general-principle)
+    - [Start/End of activities](#startend-of-activities)
+    - [Relative date or time modifiers](#relative-date-or-time-modifiers)
+    - [Absolute time modifier](#absolute-time-modifier)
+  - [Setup](#setup)
     - [Run unit tests](#run-unit-tests)
 
 <!-- END doctoc generated TOC please keep comment here to allow auto update -->
@@ -17,13 +22,69 @@ This project is affiliated with the [Maison du logiciel libre (ML<sup>2</sup>)](
 
 Tool for instructors to plan course activities and synchronize the data with syllabus, LMS, etc.
 
-### Setup
+Moodle courses can be cloned and updated with new activity dates from a calendar. [Why?](https://github.com/fuhrmanator/course-activity-planner/blob/master/ooad/overview.md)
+
+
+## How to use
+
+### General principle
+
+Quizzes (more to come) can be planned relative to Seminars and Practicas. Each activity adapts it's start and end dates with the calendar of specific dates.
+
+`<activity to plan> <start at activity> <end at activity>`
+
+Ex: `Quiz 1 is opened on Seminar 1 and closed right before Practica 2` would be possible with this line: `Q1 S1 P2`
+
+* `Q1` stands for Quiz 1
+* `S1` stands for Seminar 1
+* `P2` stands for Practica 2
+
+### Start/End of activities
+
+Adding `F` to an activity will read the finishing time of the activity. Adding nothing or `S` will read the start time.
+
+Ex: `Quiz 1 is opened right after Seminar 1 and closed right after Practica 1` would be `Q1 S1F P1F`
+
+
+### Relative date or time modifiers
+
+Amounts of time can be subtracted or added to activities.
+
+Supports `+` or `-` combined with
+
+* minutes: `m`
+* hours: `h`
+* days: `d`
+* weeks: `w`
+
+Ex: `1 hour after Seminar 1` would be `S1+1h`.
+
+Ex: `15 minutes before Practica 2` would be `P2-15m`.
+
+Ex: `Quiz 1 is opened 1 hour after Seminar 1 and closed 15 minutes before Practica 2` would be `Q1 S1+1h P2-15m`
+
+
+### Absolute time modifier
+
+The exact hours can be set to an activity.
+
+Ex: `the day of Seminar 1 at 23:55` would be `S1@23:55`.
+
+This can be used along with relative date or time modifiers.
+
+Ex: `the day before Seminar 1 at 23:55` would be `S1-1d@23:55`.
+
+**Please Note** when used with a relative modifier, the time modifier must be last.
+
+`S1-1d@23:55` is valid
+
+`S1@23:55-1d` is invalid
+
+## Setup
 * Setup a python virtualenv
 ```
 cd python && virtualenv-3.4 env
 ```
-
-### Run unit tests
 * Activate the python virtualenv
 ```
 . env/bin/activate
@@ -32,6 +93,8 @@ cd python && virtualenv-3.4 env
 ```
 pip install -r requirements.txt
 ```
+
+### Run unit tests
 * Run the test suite
 ```
 nosetests