Adding link instructions (#787)

docs/coding/object-detection.md

@@ -4,7 +4,7 @@ Design ways to avoid accidents between vehicles and objects in the road.
 
 ![Deer in the road](/static/coding/object-detection/road-deer.jpg)
 
-## Connect 
+## Connect
 
 Think about:
 
@@ -12,7 +12,7 @@ Think about:
 * What do you need to be aware of to avoid collisions with obstacles?
 * What causes traffic jams in high density areas?
 
-## Construct 
+## Construct
 
 ### Build
 
@@ -20,10 +20,16 @@ Build a @boardname@ vehicle that can avoid accidents between vehicles and object
 
 [![EV3 Robot Driving Base](/static/coding/object-detection/ev3-robot-driving-base.jpg)](https://le-www-live-s.legocdn.com/sc/media/lessons/mindstorms-ev3/building-instructions/ev3-ultrasonic-sensor-driving-base-61ffdfa461aee2470b8ddbeab16e2070.pdf)
 
-Build an obstacle for your robot to detect. You can build the **cuboid model** out of LEGO bricks or an obstacle of your choice. 
+Build an obstacle for your robot to detect. You can build the **cuboid model** out of LEGO bricks or an obstacle of your choice.
 
 [![Cubiod block](/static/coding/object-detection/ev3-cuboid.jpg)](https://le-www-live-s.legocdn.com/sc/media/lessons/mindstorms-ev3/building-instructions/ev3-cuboid-dc93b2e60bed2981e76b3bac9ea04558.pdf)
 
+### ~hint
+
+If clicking the above images doesn't open the instructions, right-click on the image and choose "Save link as..." to download the PDF.
+
+### ~
+
 ### Check
 
 Before you program, check:
@@ -38,7 +44,7 @@ Before you program, check:
 * Program your robot to detect any obstacles that might appear while the robot is moving forward (or backward).
 * Make the robot stop when it detects an object that is less than 20 cm away.
 
-Before you program, think about:  
+Before you program, think about:
 * How will you program the robot to detect obstacles?
 * How will you program the robot to stop at obstacles?
 * Which programming blocks will you use?
@@ -59,7 +65,7 @@ motors.stopAll()
 
 ### ~
 
-### Sample Solution 
+### Sample Solution
 
 1. Start the program when EV3 ``enter`` button is pressed.
 2. Turn motors ``B`` and ``C`` on at speed ``50``.
@@ -80,7 +86,7 @@ Click **Download** and follow the instructions to get your code onto your EV3 Br
 
 ## Contemplate
 
-On the road, when a driver sees and object, they slow their car down before coming to a full stop. 
+On the road, when a driver sees and object, they slow their car down before coming to a full stop.
 
 Program your EV3 Driving Base to do the same.
 
@@ -93,7 +99,7 @@ If the Ultrasonic Sensor:
 ### ~hint
 
 Consider using this block in your solution:
- 
+
 ```block
 if (true) {
 }
@@ -101,7 +107,7 @@ if (true) {
 
 ### ~
 
-### Sample Solution 
+### Sample Solution
 
 ```blocks
 loops.forever(function () {
@@ -118,7 +124,7 @@ loops.forever(function () {
 
 Click **Download** and follow the instructions to get your code onto your EV3 Brick. Press the ``center`` button on the EV3 Brick to run the program.
 
-## Continue 
+## Continue
 
 * Get together with other building teams and make a traffic jam by placing all of your robots in a line with varying amounts of space between them.
 * Have everyone start their robots at the same time and see what happens.
@@ -130,8 +136,8 @@ Click **Download** and follow the instructions to get your code onto your EV3 Br
 
 * Share what you think “efficiency in programming” means.
 * Explore the different solutions other programmers came up with.
-* Create a video of your project, especially your final presentation and your robot’s performance. Explain some important features of your software program. 
-* Include an image of your program with comments. 
-* Add a team photograph! 
+* Create a video of your project, especially your final presentation and your robot’s performance. Explain some important features of your software program.
+* Include an image of your program with comments.
+* Add a team photograph!
 
 Congratulations! What will you design next?