Add some comments to distinguish code from different days

aoc20.lisp

@@ -1,5 +1,7 @@
 ;;;; AoC 2020
 
+;;; Day 1
+
 (defun read-1 (file)
   (with-open-file (stream file)
     (loop for line = (read-line stream nil)
@@ -32,6 +34,8 @@
 	  (print (solve-1-1 data target))
 	  (print (solve-1-2 data target)))))
 
+;;; Day 2
+
 (defstruct password
   (pchar)
   (prange)
@@ -74,6 +78,8 @@
     (time (progn (print (%solve-2 data #'%solve-2-1))
 		 (print (%solve-2 data #'%solve-2-2))))))
 
+;;; Day 3
+
 (defun read-3 (file)
   (with-open-file (stream file)
     (let ((temp-map (loop for line = (read-line stream nil)
@@ -116,6 +122,8 @@
 	  (print (solve-3-1 '(1 3) data))
 	  (print (solve-3-2 '((1 1) (1 3) (1 5) (1 7) (2 1)) data)))))
 
+;;; Day 4
+
 (defvar *passport-fields* (list "byr" "iyr" "eyr" "hgt" "hcl" "ecl" "pid" "cid"))
 (defvar *passport-rules-broken* (list nil nil nil nil nil nil nil (lambda (n) (declare (ignore n)) t)))
 (defvar *passport-rules* nil)
@@ -184,6 +192,8 @@
 		   #\0 (elt bits 0) string))
 		 :radix 2))
 
+;;; Day 5
+
 (defun read-5 (file)
   (with-open-file (stream file)
     (loop for line = (read-line stream nil)
@@ -213,6 +223,8 @@
 		 (solve-5-2 data)
 		 (print p1-answer)))))
 
+;;; Day 6
+
 (defun read-forms (stream)
   (loop for line = (read-line stream nil)
 	while (and line (not (string= line "")))