txt: simple command line text editor

Built to run on linux with no dependencies. Seems to die on mac, unfortunate.

Like vim I guess. Command line text editor.

Current features:

create file
edit and save file
Vim commands (d, A, i, w, q, hjkl, gg, dd, G, o, $, probably a few more I forgot)
- see editor_actions.c
Line macro and macro recording
- :norm repeat typed commands on visual selection row by row
- q record commands as they are typed, and play back
Preserve indent
- probably dies on some edge cases
Enter visual mode (single line) by pressing v, or multi-line by pressing V.
Search for a character inline by pressing f (forwards) or F (backwards), then the character to search for. NORMAL mode only.
Search for words across lines by pressing / (forwards) or ? (backwards), then the text to search for followed by ENTER. NORMAL mode only.

Requirements: gcc 9.3, valgrind, POSIX OS

make or make all: Builds the editor, in ./bin/main
make test: Run test cases
make valgrind_test: Run test cases, with valgrind
- Note: The editor uses design patterns that result in "still reachable" memory, that is OK
sudo make install: Copy binary to /usr/local/bin
- lol it works on my machine

tests: test files/testplan
editor: editor specific stuff
structures: generic data structures (kinda? buffer is in here for now, might move it)
bin: binaries (test, main) go here

weekX-dev: Used to view diffs between week 1/2/3 and main.
main: up-to-date, working code. Merge requests to main should be viewed for grading purposes.
jcp-dev: Jing's weekly development branch
daniel-week-X: Daniel's weekly development branch.

more unit test
non ascii char (multi space char, <1 space char)
Move options to config file (ex. line number, tab width, expandtab should be not be configured via code)