Update project `Makefile` to render `quarto` book

Update project Makefile for building a quarto book and automating package development tasks.

New build rule book replaces scripts/render_book.R
- Render quarto book from *.qmd source files to multiple output formats
- Utilize project profile _quarto-<profile>.yml files to render html, pdf, and docx documents
Update executable R scripts
- exec/coverage.R
- Calculate package unit testing coverage
- Ignore deprecated functions with .covrignore
- exec/readme.R
- Renders project root and data-raw/ README via rmarkdown::render()
Improve Makefile syntax for rendering package *.rda files from data-raw/*.R scripts
- Begin standardization of exported package data names

Current	Target	Prerequisite `data-raw/`	Recipe
herbarium_specimens.rda	vouchers.rda	specimens/vouchers.xlsx	vouchers.R
dna_specimens.rda	dna.rda	specimens/dna.csv	dna.R
seinet_coords.rda	seinet.rda	seinet/ocurrences.tab	seinet.R
spp_(color/shape).rda	aesthetics.rda	NA	aesthetics.R

jasonratcliff / thesis