fill readme

README.md

@@ -1,3 +1,104 @@
 # krontab
 
  [ ![Download](https://api.bintray.com/packages/insanusmokrassar/InsanusMokrassar/krontab/images/download.svg) ](https://bintray.com/insanusmokrassar/InsanusMokrassar/krontab/_latestVersion)
+ 
+This library was created to simplify work with from time to time things.
+
+## How to use
+
+There are several ways to configure and use this library:
+
+* From some string
+* From builder
+
+Anyway, to start some action from time to time you will need to use one of extensions/functions:
+
+```kotlin
+val kronScheduler = /* creating of KronScheduler instance */;
+
+kronScheuler.doWhile {
+    // some action
+    true // true - repeat on next time
+}
+```
+
+### Config from string
+
+Developers can use more simple way to configure repeat times is string. String configuring
+like a `crontab`, but with a little bit different meanings:
+```
+/-------- Seconds
+| /------ Minutes
+| | /---- Hours
+| | | /-- Days of months
+| | | | / Months
+| | | | |
+* * * * *
+```
+
+It is different with original `crontab` syntax for the reason, that expected that in practice developers
+will use seconds and minutes with more probability than months (for example). In fact, developers will use something
+like:
+
+```kotlin
+doWhile("/5 * * * *") {
+    println("Called")
+    true // true - repeat on next time
+}
+```
+
+Or more version:
+
+```kotlin
+doInfinity("/5 * * * *") {
+    println("Called")
+}
+```
+
+Both of examples will print `Called` message every five seconds.
+
+### Config via builder
+
+Also this library currently supports DSL for creating the same goals:
+
+```kotlin
+val kronScheduler = buildSchedule {
+    seconds {
+        from (0) every 5
+    }
+}
+kronScheduler.doWhile {
+    println("Called")
+    true // true - repeat on next time
+}
+```
+
+Or
+
+```kotlin
+val kronScheduler = buildSchedule {
+    seconds {
+        0 every 5
+    }
+}
+kronScheduler.doWhile {
+    println("Called")
+    true // true - repeat on next time
+}
+```
+
+Or
+
+```kotlin
+val kronScheduler = buildSchedule {
+    seconds {
+        0 every 5
+    }
+}
+kronScheduler.doInfinity {
+    println("Called")
+}
+```
+
+All of these examples will do the same things: print `Called` message every five seconds.
+