Revise docs (#416)

* chore: add license badge to README

* perf(docs): ignore node_modules in markdown preprocessor

* docs: remove tabs for install commands on homepage

* docs(button-set): improve copy

* docs(button): improve usage for icon-only, link buttons

* docs: various copy improvements

docs/src/pages/components/Button.svx

@@ -42,10 +42,18 @@ description: High-level description
 
 ### Icon-only button
 
-<Button icon={Add16} hasIconOnly tooltipPosition="bottom" tooltipAlignment="center" iconDescription="Tooltip text" />
+Set `hasIconOnly` to `true` to use the icon-only button variant.
+
+**Note:** you must provide an `iconDescription` for the button tooltip.
+
+The tooltip position and alignment can be controlled by the `tooltipPosition`, `tooltipAlignment` props, respectively.
+
+<Button hasIconOnly tooltipPosition="bottom" tooltipAlignment="center" iconDescription="Tooltip text" icon={Add16} />
 
 ### Link button
 
+If an `href` value is specified, the component will render an [anchor element](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/a) with a "button" role.
+
 <Button href="#">Link button</Button>
 
 ### Custom element

docs/src/pages/components/ButtonSet.svx

@@ -8,7 +8,9 @@ source: Button/ButtonSet.svelte
   import Preview from "../../components/Preview.svelte";
 </script>
 
-### Default (juxtaposed)
+### Default
+
+Buttons in a button set are juxtaposed by default.
 
 <ButtonSet>
   <Button kind="secondary">Cancel</Button>
@@ -17,6 +19,8 @@ source: Button/ButtonSet.svelte
 
 ### Stacked
 
+Set `stacked` to `true` to use the stacked variant.
+
 <ButtonSet stacked>
   <Button icon={Login16}>Log in</Button>
   <Button kind="ghost">Sign up</Button>

docs/src/pages/components/Search.svx

@@ -5,7 +5,7 @@
 
 ### Default
 
-The `Search` component is extra-large by default. There are [large](#large-size) and [small](#small-size) size variants.
+The `Search` component size is extra-large by default. There are [large](#large-size) and [small](#small-size) size variants.
 
 <Search />