fix broken code block in install section

docs/plugins/audio-button-response.md

@@ -63,6 +63,7 @@ npm install @jspsych/plugin-audio-button-response
 ```
 ```js
 import audioButtonResponse from '@jspsych/plugin-audio-button-response';
+```
 
 ## Examples
 

docs/plugins/audio-keyboard-response.md

@@ -61,6 +61,7 @@ npm install @jspsych/plugin-audio-keyboard-response
 ```
 ```js
 import audioKeyboardResponse from '@jspsych/plugin-audio-keyboard-response';
+```
 
 ## Examples
 

docs/plugins/audio-slider-response.md

@@ -68,6 +68,7 @@ npm install @jspsych/plugin-audio-slider-response
 ```
 ```js
 import audioSliderResponse from '@jspsych/plugin-audio-slider-response';
+```
 
 ## Examples
 

docs/plugins/browser-check.md

@@ -96,6 +96,7 @@ npm install @jspsych/plugin-browser-check
 ```
 ```js
 import browserCheck from '@jspsych/plugin-browser-check';
+```
 
 ## Examples
 

docs/plugins/call-function.md

@@ -45,6 +45,7 @@ npm install @jspsych/plugin-call-function
 ```
 ```js
 import callFunction from '@jspsych/plugin-call-function';
+```
 
 ## Examples
 

docs/plugins/canvas-button-response.md

@@ -53,6 +53,7 @@ npm install @jspsych/plugin-canvas-button-response
 ```
 ```js
 import canvasButtonResponse from '@jspsych/plugin-canvas-button-response';
+```
 
 ## Examples
 

docs/plugins/canvas-keyboard-response.md

@@ -50,6 +50,7 @@ npm install @jspsych/plugin-canvas-keyboard-response
 ```
 ```js
 import canvasKeyboardResponse from '@jspsych/plugin-canvas-keyboard-response';
+```
 
 ## Examples
 

docs/plugins/canvas-slider-response.md

@@ -57,6 +57,7 @@ npm install @jspsych/plugin-canvas-slider-response
 ```
 ```js
 import canvasSliderResponse from '@jspsych/plugin-canvas-slider-response';
+```
 
 ## Examples