One more README update

Author: tachyonlabs

README.md

@@ -6,27 +6,27 @@ My situation: I already completed the July/August 2017 version of your Alumni In
 
 As I said in [my InterviewBit profile gif](https://github.com/tachyonlabs/CodePath-Alumni-Professional-Interview-Prep-Course/blob/master/interviewbit-profile.gif), I've actually been using InterviewBit off and on since March (though I still have a ways to go before reaching Code Ninja status). My profile is https://www.interviewbit.com/profile/Tachyon
 
-### Checkpoint 1
+#### Checkpoint 1
 Checkpoint Level 1 is just a multiple-choice question on time complexity, not a coding problem, but this repo includes a screenshot of it with my answer:
 
 * https://github.com/tachyonlabs/CodePath-Alumni-Professional-Interview-Prep-Course/blob/master/interviewbit_checkpoint_1.jpg
 
-### Checkpoint 2
+#### Checkpoint 2
 * https://github.com/tachyonlabs/CodePath-Alumni-Professional-Interview-Prep-Course/blob/master/interviewbit_checkpoint_2_prettyprint.py
 
-### Checkpoint 3
+#### Checkpoint 3
 For some reason [my profile](https://www.interviewbit.com/profile/Tachyon) is showing Level-Ups for Levels 1, 2, 4, and 5, but not 3, even though among other things I did the Checkpoint Level 3 prework problems below. Here also is [a screenshot of the Checkpoint Level 3 screen.](https://github.com/tachyonlabs/CodePath-Alumni-Professional-Interview-Prep-Course/blob/master/interviewbit_checkpoint_3.jpg)
 
 * https://github.com/tachyonlabs/CodePath-Alumni-Professional-Interview-Prep-Course/blob/master/interviewbit_checkpoint_3_kth-smallest-element-in-the-array.py
 * https://github.com/tachyonlabs/CodePath-Alumni-Professional-Interview-Prep-Course/blob/master/interviewbit_checkpoint_3_numrange.py
 
-### Checkpoint 4
+#### Checkpoint 4
 * https://github.com/tachyonlabs/CodePath-Alumni-Professional-Interview-Prep-Course/blob/master/interviewbit_checkpoint_4_subtract.py
 * https://github.com/tachyonlabs/CodePath-Alumni-Professional-Interview-Prep-Course/blob/master/interviewbit_checkpoint_4_nextgreater.py
 
-### Checkpoint 5
+#### Checkpoint 5
 * https://github.com/tachyonlabs/CodePath-Alumni-Professional-Interview-Prep-Course/blob/master/interviewbit_checkpoint_5_all-unique-permutations.py
 * https://github.com/tachyonlabs/CodePath-Alumni-Professional-Interview-Prep-Course/blob/master/interviewbit_checkpoint_5_longest-consecutive-sequence.py
 
-### HackerRank Calibration Test
+#### HackerRank Calibration Test
 I took the HackerRank Calibration Test on November 13, and finished five of the six questions -- on one hand I assume you should have received my results by now, but on the other hand I never received an email confirmation after submitting it, whereas with the HackerRank tests I took during the July/August session, I did receive confirmations.