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

data_structures_and_algorithms/conways-game-of-life.py

@@ -1,78 +0,0 @@
-from itertools import product
-from random import choice
-from time import sleep
-from os import system
-from math import floor
-from colorama import Back, Fore, Style
-
-################################################################################
-# Simulation of Conway's Game of Life. The goal here was to write this with a
-# small amount of code as a proof-of-concept that could be run in the terminal.
-#
-# If you'd like to tinker with the rules, see the conditionals defined in the
-# `advance/1` function. For other parameters, like the board size and refresh
-# rate, refer to the while-loop defined at the bottom of this file.
-################################################################################
-
-
-def init_board(n, init_alive_percentage):
-    """Initialize a board of size `n` by `n`. Supply a percentage,
-    `init_alive_percentage`, representing the number of cells in the board that
-    should be alive from the start."""
-    alive_count = floor(n * init_alive_percentage)
-    distribution = [True] * alive_count + [False] * (n - alive_count)
-    return [[choice(distribution) for _ in range(n)] for _ in range(n)]
-
-
-def neighbors(coord, board):
-    """Return the neighbors for a given `coord` on a `board`."""
-    n = len(board)
-    row, col = coord
-    return [
-        board[(row + row_d) % n][(col + col_d) % n]
-        for row_d, col_d in product([-1, 0, 1], [-1, 0, 1])
-        if (row_d, col_d) != (0, 0)
-    ]
-
-
-def advance(board):
-    """Advance the state of the `board` from T[n] to T[n+1]."""
-    n = len(board)
-    new_board = [[False for _ in range(n)] for _ in range(n)]
-    for row in range(n):
-        for col in range(n):
-            alive_count = len([x for x in neighbors((row, col), board) if x])
-            # Loneliness
-            if alive_count == 0:
-                new_board[row][col] = False
-            # Status Quo
-            elif alive_count == 1:
-                new_board[row][col] = board[row][col]
-            # Cooperation
-            elif alive_count == 2:
-                new_board[row][col] = True
-            # Resource starvation
-            elif alive_count >= 3:
-                new_board[row][col] = False
-    return new_board
-
-
-def print_board(board):
-    """Print the game `board` in a human-readable way."""
-    result = ''
-    for row in board:
-        for col in row:
-            if col:
-                result += Back.GREEN + '1 ' + Style.RESET_ALL
-            else:
-                result += Back.RED + '0 ' + Style.RESET_ALL
-        result += '\n'
-    print(result)
-
-
-board = init_board(100, 0.50)
-while True:
-    system('clear')
-    print_board(board)
-    sleep(0.15)
-    board = advance(board)