Add links to the examples, some option values, documentation contribution instructions

Author: cmarmo

CONTRIBUTING.md

@@ -76,3 +76,22 @@ To add an example to the static examples:
 - Add appropriate link in: `docs/source/examples.rst`
 - Add the example name to the `EXAMPLES` in `docs/source/conf.py`
 - Add `ignore-links` config in `package.json`
+
+## Documentation
+
+The documentation is built with [sphinx](https://www.sphinx-doc.org/en/master/)
+making use of the [PyData Sphinx theme](https://pydata-sphinx-theme.readthedocs.io/en/stable/index.html).
+
+To build it locally
+- create and activate an isolated development environment with the necessary dependencies
+with
+```bash
+conda env create -f docs/environment.yml
+conda activate lumino_documentation
+```
+- build, for example the html version, with
+```bash
+cd docs
+make html
+```
+The HTML pages are then located in the `build/html` directory.

packages/datagrid/src/datagrid.ts

@@ -52,6 +52,9 @@ import { TextRenderer } from './textrenderer';
  * the child widgets of a data grid directly is undefined behavior.
  *
  * This class is not designed to be subclassed.
+ * 
+ * See also the related [example](../../examples/datagrid/index.html) and
+ * its [source](https://github.com/jupyterlab/lumino/tree/main/examples/example-datagrid).
  */
 export class DataGrid extends Widget {
   /**

packages/widgets/src/accordionpanel.ts

@@ -15,12 +15,16 @@ import { Widget } from './widget';
  *
  * #### Notes
  * This class provides a convenience wrapper around {@link AccordionLayout}.
+ * 
+ * See also the related [example](../../examples/accordionpanel/index.html) and
+ * its [source](https://github.com/jupyterlab/lumino/tree/main/examples/example-accordionpanel).
  */
 export class AccordionPanel extends SplitPanel {
   /**
    * Construct a new accordion panel.
    *
    * @param options - The options for initializing the accordion panel.
+   * 
    */
   constructor(options: AccordionPanel.IOptions = {}) {
     super({ ...options, layout: Private.createLayout(options) });

packages/widgets/src/boxpanel.ts

@@ -120,13 +120,17 @@ export namespace BoxPanel {
     /**
      * The layout direction of the panel.
      *
+     * Possible values are documented in {@link BoxLayout.Direction}.
+     *
      * The default is `'top-to-bottom'`.
      */
     direction?: Direction;
 
     /**
      * The content alignment of the panel.
      *
+     * Possible values are documented in {@link BoxLayout.Alignment}.
+     *
      * The default is `'start'`.
      */
     alignment?: Alignment;

packages/widgets/src/dockpanel.ts

@@ -31,6 +31,10 @@ import { Widget } from './widget';
 
 /**
  * A widget which provides a flexible docking area for widgets.
+ * 
+ * #### Notes
+ * See also the related [example](../../examples/dockpanel/index.html) and
+ * its [source](https://github.com/jupyterlab/lumino/tree/main/examples/example-dockpanel).
  */
 export class DockPanel extends Widget {
   /**

packages/widgets/src/menubar.ts

@@ -33,6 +33,10 @@ import { Widget } from './widget';
 
 /**
  * A widget which displays menus as a canonical menu bar.
+ *
+ * #### Notes
+ * See also the related [example](../../examples/menubar/index.html) and
+ * its [source](https://github.com/jupyterlab/lumino/tree/main/examples/example-menubar).
  */
 export class MenuBar extends Widget {
   /**

packages/widgets/src/splitlayout.ts

@@ -744,13 +744,17 @@ export namespace SplitLayout {
     /**
      * The orientation of the layout.
      *
+     * Possible values are documented in {@link SplitLayout.Orientation}.
+     * 
      * The default is `'horizontal'`.
      */
     orientation?: Orientation;
 
     /**
      * The content alignment of the layout.
      *
+     * Possible values are documented in {@link SplitLayout.Alignment}.
+     *
      * The default is `'start'`.
      */
     alignment?: Alignment;