Small doc fixes and many tiny edits. (#439)

docs/courses/csintro/iteration/activity.md

@@ -114,7 +114,7 @@ If there is time, let the students experiment with changing the parameters to se
 
 We just used the first of the 3 different types of Loop blocks available to us. What about the other 2 loop blocks, ‘while’ and ‘for’?
 
-## ‘For’ block: Traveling light
+## ‘For’ block: traveling light
 
 The ‘for’ block is useful when you have a variable in your loop that you want to change by a fixed amount within a specific range each time through a loop.  What does this mean? Let’s look at an example.
 
@@ -265,4 +265,4 @@ Example Pseudocode:
 
 _When someone shakes the micro:bit, while button A is not pressed, play the two tone alarm twice. Keep playing the alarm tones until the user presses the A button._
 
-To use sound with your micro:bit, you will need to connect it to some speakers or headphones. See how to do this here:  https://pxt.microbit.org/projects/hack-your-headphones
+To use sound with your micro:bit, you will need to connect it to some speakers or headphones. See how to do this here: [Hack you headphones](/projects/hack-your-headphones).

docs/courses/csintro/iteration/project.md

@@ -68,9 +68,9 @@ Have students write a reflection of about 150–300 words, addressing the follow
 `*` Uses loops in a way that is integral to the program<br/>
 `*` Compiles and runs as intended<br/>
 `*` Meaningful comments in code<br/>
-**3 =** micro:bit program lacks 1 of the required elements<br/>
-**2 =** micro:bit program lacks 2 of the required elements<br/>
-**1 =** micro:bit program lacks 3 or more of the required elements
+**3 =** micro:bit program lacks 1 of the required elements.<br/>
+**2 =** micro:bit program lacks 2 of the required elements.<br/>
+**1 =** micro:bit program lacks 3 or more of the required elements.
 
 ### Collaboration reflection
 **4 =** Reflection piece includes:<br/>