Add a usage section to readme

Author: marijnh

README.md

@@ -19,19 +19,26 @@ we have a [code of
 conduct](http://contributor-covenant.org/version/1/1/0/) that applies
 to communication around the project.
 
+## Usage
+
+```javascript
+import {EditorView, basicSetup} from "codemirror"
+import {python} from "@codemirror/lang-python"
+
+const view = new EditorView({
+  parent: document.body,
+  doc: `print("Hello world")`,
+  extensions: [basicSetup, python()]
+})
+```
+
 # API Reference
 
 <dl>
-<dt id="user-content-globalcompletion">
-  <code><strong><a href="#user-content-globalcompletion">globalCompletion</a></strong>: <a href="https://codemirror.net/docs/ref#autocomplete.CompletionSource">CompletionSource</a></code></dt>
-
-<dd><p>Autocompletion for built-in Python globals and keywords.</p>
-</dd>
-<dt id="user-content-localcompletionsource">
-  <code><strong><a href="#user-content-localcompletionsource">localCompletionSource</a></strong>(<a id="user-content-localcompletionsource^context" href="#user-content-localcompletionsource^context">context</a>: <a href="https://codemirror.net/docs/ref#autocomplete.CompletionContext">CompletionContext</a>) → <a href="https://codemirror.net/docs/ref#autocomplete.CompletionResult">CompletionResult</a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/null">null</a></code></dt>
+<dt id="user-content-python">
+  <code><strong><a href="#user-content-python">python</a></strong>() → <a href="https://codemirror.net/docs/ref#language.LanguageSupport">LanguageSupport</a></code></dt>
 
-<dd><p>Completion source that looks up locally defined names in
-Python code.</p>
+<dd><p>Python language support.</p>
 </dd>
 <dt id="user-content-pythonlanguage">
   <code><strong><a href="#user-content-pythonlanguage">pythonLanguage</a></strong>: <a href="https://codemirror.net/docs/ref#language.LRLanguage">LRLanguage</a></code></dt>
@@ -40,9 +47,15 @@ Python code.</p>
 parser</a>, extended with
 highlighting and indentation information.</p>
 </dd>
-<dt id="user-content-python">
-  <code><strong><a href="#user-content-python">python</a></strong>() → <a href="https://codemirror.net/docs/ref#language.LanguageSupport">LanguageSupport</a></code></dt>
+<dt id="user-content-globalcompletion">
+  <code><strong><a href="#user-content-globalcompletion">globalCompletion</a></strong>: <a href="https://codemirror.net/docs/ref#autocomplete.CompletionSource">CompletionSource</a></code></dt>
 
-<dd><p>Python language support.</p>
+<dd><p>Autocompletion for built-in Python globals and keywords.</p>
+</dd>
+<dt id="user-content-localcompletionsource">
+  <code><strong><a href="#user-content-localcompletionsource">localCompletionSource</a></strong>(<a id="user-content-localcompletionsource^context" href="#user-content-localcompletionsource^context">context</a>: <a href="https://codemirror.net/docs/ref#autocomplete.CompletionContext">CompletionContext</a>) → <a href="https://codemirror.net/docs/ref#autocomplete.CompletionResult">CompletionResult</a> | <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/null">null</a></code></dt>
+
+<dd><p>Completion source that looks up locally defined names in
+Python code.</p>
 </dd>
-</dl>
+</dl>

src/README.md

@@ -19,8 +19,25 @@ we have a [code of
 conduct](http://contributor-covenant.org/version/1/1/0/) that applies
 to communication around the project.
 
+## Usage
+
+```javascript
+import {EditorView, basicSetup} from "codemirror"
+import {python} from "@codemirror/lang-python"
+
+const view = new EditorView({
+  parent: document.body,
+  doc: `print("Hello world")`,
+  extensions: [basicSetup, python()]
+})
+```
+
 # API Reference
 
 @python
 
-@pythonLanguage
+@pythonLanguage
+
+@globalCompletion
+
+@localCompletionSource