Docs: adding first version of the auto-generated packages API docs. (#22107)

* trying out api-extractor.

* works with our setup of build.

* wip.

* changed the packages so it works better with the api-extractor.

* Changes to make the api-extractor to work.

* cleaned up the api-extractor config files.

* added some more documentation.

* added tsdoc-metadata to gitignore.

* removed the generated docs (will do that in another PR).

* added execute permission to script for generating dosc.

* added so we will push generated docs to branch.

* will clean packages_api on abort.

* Fixed failing tests.

* fixed formatting issue with typedoc comment.

* temporarily disabled tslint rules about namespace until https://github.com/microsoft/rushstack/issues/1029 is resolved

* temporary enabled bable namespaces.

* updated build script.

* updated script.

* updated script with some colors.

* changed to camelCase.

* removed spacing.

* Starting to add documentation guidelines.

* added examples headline.

* added menu options.

* added parameters and return values.

* Fixed merge error.

* Added first version of auto-generated docs.

* changed so we use the eslint ignore syntax.

* changed to correct eslint ingnore comment.

* fixed some spelling errors reported by codespell.

* added script to generate docs in current folder.

* updated api docs.

* lerna bootstrap.

* added eror to the ingore words list.

* removed file that should be ignored.

* updated locKFILE.

* referenced the code comments guidelines.

* updated packages.

* updated deps.

* updated the autogenerated dosc.

* adding missing new line.

docs/sources/packages_api/ui/bargauge.md

@@ -0,0 +1,107 @@
++++
+# -----------------------------------------------------------------------
+# Do not edit this file. It is automatically generated by API Documenter.
+# -----------------------------------------------------------------------
+title = "BarGauge"
+keywords = ["grafana","documentation","sdk","@grafana/ui"]
+type = "docs"
+draft = true
++++
+
+## BarGauge class
+
+<b>Signature</b>
+
+```typescript
+export declare class BarGauge extends PureComponent<Props> 
+```
+<b>Import</b>
+
+```typescript
+import { BarGauge } from '@grafana/ui';
+```
+<b>Properties</b>
+
+|  Property | Modifiers | Type | Description |
+|  --- | --- | --- | --- |
+|  [defaultProps](#defaultprops-property) | <code>static</code> | <code>Partial&lt;Props&gt;</code> |  |
+
+<b>Methods</b>
+
+|  Method | Modifiers | Description |
+|  --- | --- | --- |
+|  [getCellColor(positionValue)](#getcellcolor-method) |  |  |
+|  [render()](#render-method) |  |  |
+|  [renderBarAndValue()](#renderbarandvalue-method) |  |  |
+|  [renderBasicAndGradientBars()](#renderbasicandgradientbars-method) |  |  |
+|  [renderRetroBars()](#renderretrobars-method) |  |  |
+
+### defaultProps property
+
+<b>Signature</b>
+
+```typescript
+static defaultProps: Partial<Props>;
+```
+
+### getCellColor method
+
+<b>Signature</b>
+
+```typescript
+getCellColor(positionValue: TimeSeriesValue): CellColors;
+```
+<b>Parameters</b>
+
+|  Parameter | Type | Description |
+|  --- | --- | --- |
+|  positionValue | <code>TimeSeriesValue</code> |  |
+
+<b>Returns:</b>
+
+`CellColors`
+
+### render method
+
+<b>Signature</b>
+
+```typescript
+render(): JSX.Element;
+```
+<b>Returns:</b>
+
+`JSX.Element`
+
+### renderBarAndValue method
+
+<b>Signature</b>
+
+```typescript
+renderBarAndValue(): React.ReactNode;
+```
+<b>Returns:</b>
+
+`React.ReactNode`
+
+### renderBasicAndGradientBars method
+
+<b>Signature</b>
+
+```typescript
+renderBasicAndGradientBars(): ReactNode;
+```
+<b>Returns:</b>
+
+`ReactNode`
+
+### renderRetroBars method
+
+<b>Signature</b>
+
+```typescript
+renderRetroBars(): ReactNode;
+```
+<b>Returns:</b>
+
+`ReactNode`
+