message: Added breaking changes migration guide for time scale API
diff: -# Version 3.0 breaking change
  +# Version 3.0 breaking changes
  +
  +Lightweight charts library 3.0 announces the major improvements: supporting two price scales and improving the time scale API.
  +In order of keeping API clear and consistent, we decided to allow breaking change of the API.
  +
  +In this document you can find migration guide from previous version to 3.0.
  +
  +## Time Scale API
  +
  +Previously to handle changing visible time range you needed to use `subscribeVisibleTimeRangeChange` and `unsubscribeVisibleTimeRangeChange` to subscribe and unsubscribe from visible range event.
  +These methods were available in the chart object (e.g. you call it like `chart.subscribeVisibleTimeRangeChange(func)`).
  +
  +In 3.0 in order to make API more consistency with the new API we decided to move these methods to [time scale API](./time-scale.md)
  +(along with the new subscription methods [`subscribeVisibleLogicalRangeChange`](./time-scale.md#subscribevisiblelogicalrangechange) and [`unsubscribeVisibleLogicalRangeChange`](./time-scale.md#unsubscribevisiblelogicalrangechange)).
  +
  +So, to migrate your code to 3.0 you need to just replace:
  +
  +- `chart.subscribeVisibleTimeRangeChange` with `chart.timeScale().subscribeVisibleTimeRangeChange`
  +- `chart.unsubscribeVisibleTimeRangeChange` with `chart.timeScale().unsubscribeVisibleTimeRangeChange`
  +
  +## Two price scales
  -Lighweight charts library 3.0 announces the major improvement: supporting two price scales.
  -In order of keeping API clear and consistent, we desided to allow breaking change of the API.
  We understand disadvantages of breaking changes in the API, so we have not removed support of the current API at all, but have deprecated it, so the most common cases will continue working.
  -You could refer new API [here](./price-scale.md)
  +
  +You could refer new API [here](./price-scale.md).
  Following are migration rules.
  -## Default behavior
  +### Default behavior
  -Default behavior is not changed. If you do not specify price scale options, the chart will have right price scale visible and all the serieses will assign to it.
  +Default behavior is not changed. If you do not specify price scale options, the chart will have right price scale visible and all the series will assign to it.
  -## Left price scale
  +### Left price scale
  If you need the price scale to be drawn on the left side, you should make following changes.
  instead of
  @@ -47,7 +66,7 @@ var histSeries = chart.addHistogramSeries({
  New version fully supports this case via old API, however this support will be removed in the future releases.
  -## No price scale
  +### No price scale
  To create chart without any visible price scale, instead of
  @@ -74,7 +93,7 @@ var chart = LightweightCharts.createChart(container, {
  New version fully supports this case via old API, however this support will be removed in the future releases.
  -## Creating overlay
  +### Creating overlay
  To create an overlay series, instead of
  @@ -95,7 +114,7 @@ var histogramSeries = chart.addHistogramSeries({
  New version fully supports this case via old API, however this support will be removed in the future releases.
  -## Move price scale from right to left or vice versa
  +### Move price scale from right to left or vice versa
  To do this, instead of
  @@ -104,7 +123,7 @@ var chart = LightweightCharts.createChart(container);
  var mainSeries = chart.addLineSeries();
  -...
  +// ...
  chart.applyOptions({
  priceScale: {
  @@ -120,7 +139,7 @@ var chart = LightweightCharts.createChart(container);
  var mainSeries = chart.addLineSeries();
  -...
  +// ...
  chart.applyOptions({
  leftPriceScale: {
  @@ -132,9 +151,8 @@ chart.applyOptions({
  });
  mainSeries.applyOptions({
  - priceScaleId: 'left,
  + priceScaleId: 'left',
  });
  -
  ```
  New version does not support this case via old API, so, if you use it, you should migrate your code in order of keeping it working.
  