[MACROS][ISSUE-52]: added support for @timestamp annotation (#55)

* [MACROS][ISSUE-52]: refactoring MacroImpl, added @timestamp annotations

* [MACROS][ISSUE-52]: some experimenting with macro

* [MACROS][ISSUE-52]: integration of timestamp functionality in macro readers

* [MACROS][ISSUE-52]: added support for @timestamp annotation

* [MACROS][ISSUE-52]: update documents

* [MACROS][ISSUE-52]: setting version 0.2.3

docs/macros.md

@@ -6,19 +6,39 @@ To use it, add to your `build.sbt`:
 ```
 libraryDependencies += "com.github.fsanaulla" %% "chronicler-macros" % <version>
 ```
-## Usage
+## Tag
+All [tag](https://docs.influxdata.com/influxdb/v1.5/concepts/glossary/#tag)'s field must be marked with `@tag`. It's can be  used for optional fields.
+
+Supported types: **`String`**, **`Option[String]`**
+
+## Field
+All [field](https://docs.influxdata.com/influxdb/v1.5/concepts/glossary/#field)'s must be market with `@field` annotation. 
+
+Supported types: **`Int`**, **`Long`**, **`Double`**, **`Boolean`**, **`String`**.
+
+## Timestamp
+You can specify which field will be used as a influx [timestamp](https://docs.influxdata.com/influxdb/v1.5/concepts/glossary/#timestamp) in process serialization/deserialization by marking with `@timestamp` annotation.
+It's optional field. If it's not specified, time will be generated on database level. Otherwise will be setted from entity. 
+
+**Remember**: InfluxDB use nano precision.
+
+Supported type: **Long**.
+
+# Usage
 Feel the power of Macros.
 Let's start from reader example:
-```
-case class Entity(@tag name: String, @field age: Int)
+```scala
+case class Entity(@tag name: String,
+                  @field age: Int, 
+                  @timestamp time: Long)
 
 // that's all, after compilation, at this place will apper valid InfluxReader[T]
 implicit val rd: InfluxReader[Entity] = Macros.reader[Entity]
 
 // it's required for using type method, such
 ```
 For writer it's little bit differ, because you need specify [tag](https://docs.influxdata.com/influxdb/v1.5/concepts/key_concepts/#tag-key) and [field](https://docs.influxdata.com/influxdb/v1.5/concepts/key_concepts/#field-value). It can be done by simply annotating:
-```
+```scala
 case class Entity(@tag name: String, @field age: Int)
 
 // that's all, after compilation, at this place will apper valid InfluxWriter[T]
@@ -28,12 +48,13 @@ implicit val wr: InfluxWriter[Entity] = Macros.writer[Entity]
 meas.write[Entity](Entity("Martin", 54)
 ```
 You can add both of them in the scope by using:
-```
-implicit val fmt = Macros.format[Entity]
+```scala
+implicit val fmt: InfluxFormatter[Entity] = Macros.format[Entity]
 
 meas.write[Entity](Entity("Martin", 54)
 db.read[Entity]("SELECT * FROM some_meas")
 ```
+
 In short it's look like:
-1. Mark tags(`@tag`) and fields(`@field`).
+1. Mark tags(`@tag`) and fields(`@field`), and optional (`@timestamp`).
 2. Generate reader/writer/formatter.