Add Makefile to support make checkstyle, make format, `make runTe…

…sts` commands

CHANGELOG.md

@@ -2,6 +2,7 @@
 * [IMPROVEMENT] Added `children` property in the [LineTooltipItem](https://github.com/imaNNeoFighT/fl_chart/blob/master/repo_files/documentations/line_chart.md#linetooltipitem), [BarTooltipItem](https://github.com/imaNNeoFighT/fl_chart/blob/master/repo_files/documentations/bar_chart.md#bartooltipitem) and [ScatterTooltipItem](https://github.com/imaNNeoFighT/fl_chart/blob/master/repo_files/documentations/scatter_chart.md#scattertooltipitem) which accepts a list of [TextSpan](https://api.flutter.dev/flutter/painting/TextSpan-class.html). It allows you to have more customized texts inside the tooltip. See [BarChartSample1](https://github.com/imaNNeoFighT/fl_chart/blob/master/repo_files/documentations/bar_chart.md#sample-1-source-code) and [ScatterSample2](https://github.com/imaNNeoFighT/fl_chart/blob/master/repo_files/documentations/scatter_chart.md#sample-2-source-code), #72, #294.
 * [IMPROVEMENT] Added `getTouchLineStart` and `getTouchLineEnd` in [LineTouchData](https://github.com/imaNNeoFighT/fl_chart/blob/master/repo_files/documentations/line_chart.md#linetouchdata-read-about-touch-handling) to give more customizability over showing the touch lines. see [SampleLineChart9](https://github.com/imaNNeoFighT/fl_chart/blob/master/repo_files/documentations/line_chart.md#sample-8-source-code).
 * [IMPROVEMENT] Enabled `sectionsSpace` in PieChart for the web.
+* [IMPROVEMENT] Added [Makefile](https://makefiletutorial.com) commands which makes it comfortable for verifying your code before push (It is related to contributors, red more about it in [CONTRIBUTING.md](https://github.com/imaNNeoFighT/fl_chart/blob/master/CONTRIBUTING.md)).
 * [BUGFIX] Fixed some bugs on drawing PieChart (for example when we have only one section), #582, 
 * [BREAKING] You cannot set `0` value on [PieChartSectionData](https://github.com/imaNNeoFighT/fl_chart/blob/master/repo_files/documentations/pie_chart.md#piechartsectiondata).value anymore, instead remove it from list.
 * [BREAKING] Removed `fullHeightTouchLine` property from [LineTouchData](https://github.com/imaNNeoFighT/fl_chart/blob/master/repo_files/documentations/line_chart.md#linetouchdata-read-about-touch-handling). Now you can have a full line with following snippet:

CONTRIBUTING.md

@@ -39,14 +39,18 @@ It makes draw functions testable.
 After you have made your changes, you have to make sure your code works
 correctly and meets our guidelines. Our guidelines are:
 
-- Make sure the code passes the tests. To run tests, run `flutter test`.
+You can simply run `make checkstyle`, and if you faced any formatting problem, run `make format`.
 
-- Make sure to run `flutter analyze` and resolve any warnings or errors.
+##### Run `make checkstyle` to ensure that your code is formatted correctly
+- It runs `flutter analyze` to verify that there is no any warning or error.
+- It runs `flutter format --set-exit-if-changed --dry-run --line-length 100 .` to verify that code has formatted correctly.
 
-- The code should be formatted correctly. For Visual Studio Code users, this is
-  automatically enforced. Otherwise, you can run this command inside the
-  project from the command line: `flutter format --line-length 100 .`.
-  We use `flutter format --set-exit-if-changed --dry-run --line-length 100 .` command in CI.
+#### Run `make format` to reformat the code
+- It runs `flutter format --line-length 100 .` to format your code with 100 characters limit.
+
+
+#### Run `make runTests` to ensure that all tests are passing.
+- It runs `flutter test` under the hood.
 
 ## Creating a Pull Request
 

Makefile

@@ -0,0 +1,9 @@
+checkstyle:
+	flutter analyze; \
+	flutter format --set-exit-if-changed --dry-run --line-length 100 .
+
+format:
+	flutter format --line-length 100 .
+
+runTests:
+	flutter test