Tidy up structure of briefcase

I had a spare fifteen minutes and decided that I should tidy up my
monorepo. The work of tidying up is not finished; this is a small step in the
right direction.

TL;DR
- Created a tools directory
- Created a scratch directory (see README.md for more information)
- Added README.md to third_party
- Renamed delete_dotfile_symlinks -> symlinkManager
- Packaged symlinkManager as an executable symlink-mgr using buildGo

deepmind/part_two/todo.org

@@ -1,77 +0,0 @@
-* Array and string manipulation
-** TODO Merging Meeting Times
-** DONE Reverse String in Place
-** TODO Reverse Words
-** TODO Merge Sorted Arrays
-** TODO Cafe Order Checker
-* Hashing and hash tables
-** TODO Inflight Entertainment
-** TODO Permutation Palindrome
-** TODO Word Cloud Data
-** TODO Top Scores
-* Greedy Algorithms
-** TODO Apple Stocks
-** TODO Highest Product of 3
-** TODO Product of All Other Numbers
-** TODO Cafe Order Checker
-** TODO In-Place Shuffle
-* Sorting, searching, and logarithms
-** TODO Find Rotation Point
-** TODO Find Repeat, Space Edition
-** TODO Top Scores
-** TODO Merging Meeting Times
-* Trees and graphs
-** TODO Balanced Binary Tree
-** TODO Binary Search Tree Checker
-** TODO 2nd Largest Item in a Binary Search Tree
-** TODO Graph Coloring
-** TODO MeshMessage
-** TODO Find Repeat, Space Edition BEAST MODE
-* Dynamic programming and recursion
-** TODO Recursive String Permutations
-** TODO Compute nth Fibonacci Number
-** TODO Making Change
-** TODO The Cake Thief
-** TODO Balanced Binary Tree
-** TODO Binary Search Tree Checker
-** TODO 2nd Largest Item in a Binary Search Tree
-* Queues and stacks
-** TODO Largest Stack
-** TODO Implement A Queue With Two Stacks
-** TODO Parenthesis Matching
-** TODO Bracket Validator
-* Linked lists
-** DONE Delete Node
-** TODO Does This Linked List Have A Cycle?
-** TODO Reverse A Linked List
-** TODO Kth to Last Node in a Singly-Linked List
-** TODO Find Repeat, Space Edition BEAST MODE
-* System design
-** TODO URL Shortener
-** TODO MillionGazillion
-** TODO Find Duplicate Files
-* General programming
-** TODO Rectangular Love
-** TODO Temperature Tracker
-* Bit manipulation
-** TODO Binary Numbers
-** TODO The Stolen Breakfast Drone
-* Combinatorics, probability, and other math
-** TODO Which Appears Twice
-** TODO Find in Ordered Set
-** TODO In-Place Shuffle
-** TODO Simulate 5-sided die
-** TODO Simulate 7-sided die
-** TODO Two Egg Problem
-* JavaScript
-** TODO JavaScript Scope
-** TODO What's Wrong with This JavaScript?
-* Coding interview tips
-** TODO How The Coding Interview Works
-** TODO General Coding Interview Advice
-** TODO Impostor Syndrome
-** TODO Why You Hit Dead Ends
-** TODO Tips for Getting Unstuck
-** TODO The 24 Hours Before Your Interview
-** TODO Beating Behavioral Questions
-** TODO Managing Your Interview Timeline