✏️ edit readme and add getting started section

Author: arifyunando

README.md

@@ -1,21 +1,66 @@
 # Flogger 
 > Quick and easy to use logging library for Modern Fortran applications
 
-## Snippets
+## Features
+
+* Fast and lightweight logging library
+* Text highlighting
+* Log filtering
+* Save logs to logfile
+
+### Snippets / Examples
 
 ```f90
-a bunch of code
-```
-```sh
-echo results
+    type(FloggerUnit) :: flogs = FloggerUnit("levelClassificationTest")
+    call flogs%debug("Message Test Debug 1")
+    call flogs%info("Message Test Info 1")
+    call flogs%notice("Message Test Notice 1")
+    call flogs%warning("Message Test Warning 1")
+    call flogs%error("Message Test Error 1")
+    call flogs%fatal("Message Test Fatal 1")
 ```
+![snippets results](img/snippets.png)
 
 ## Getting Started
 
-### Manual Installation
-1. Copy the whole repository to external library folder of the target project
-2. Include library in `CMakeLists.txt` at the project root folder. 
+1. `USE` the flogger module
+
+    for every program scope, you need to `USE` the flogger module with this following command 
+    ```f90
+    USE Flogger
+    ```
+
+2. Initiate the FloggerUnit with identifier
+
+    You can initialize multiple instances of `FloggerUnit` and give different labels for each unit. Here's how to initiate the `FloggerUnit` object
+    ```f90
+    type(FloggerUnit) :: flogMain = FloggerUnit("ClassMainTest")
+    type(FloggerUnit) :: flogMidDebug = FloggerUnit("MiddleDebug")
+    type(FloggerUnit) :: flogMidWarning = FloggerUnit("MiddleWarning")
+    ```
+3. `call` the logging subroutines
+
+    To make the log message you need to call the object methods from the corresponding `FloggerUnit` instances as follows.
+    ```f90
+    call flogs%debug("Message Test Debug 2")
+    call flogs%notice("Message Test Notice 2")
+    call flogMidWarning%warning("Message Test Warning 4")
+    call flogMidWarning%error("Message Test Error 4")
+    call flogMidDebug%fatal("Message Test Fatal 4")
+    call flogMidDebug%info("Message Test Info 2")
+    ```
+
+4. Set flogger options
+
+    Flogger logging behavior can be changed using `SET_FLOGGER_OPTIONS` subroutine. Here is the example
+    ```f90
+    call SET_FLOGGER_OPTIONS(Level=FLOGS_SET_RELEASE)   ! set to release mode
+    call SET_FLOGGER_OPTIONS(Level=FLOGS_SET_SILENT)    ! set to silent mode
+    call SET_FLOGGER_OPTIONS(FileOutput=.true.)         ! make flogger build logfiles
+    ```
 
+## Documentations
+*under development...*
 
 ## Author
 **Arif Y. Sunanhadikusuma (Soen)** <br>