Add code generator for 2021 and update README

setup.sh

@@ -0,0 +1,93 @@
+#!/bin/bash
+
+mkdir $1
+
+name=$(echo $1 | awk '{print toupper(substr($0,1,1)) tolower(substr($0,2)) }')
+abbr=$(echo $2 | awk '{print substr($0,1,1) }')
+
+# Create day implementation
+echo "package $1
+
+type $name struct {
+	$2 $2
+}
+
+func Init(filepath string) *$name {
+	$1 := &$name{
+		$2: $2{},
+	}
+
+	$1.$2.load(filepath)
+	return $1
+}
+
+func (d *$name) Answer() string {
+	return \"$1 part 1 answer for $2\"
+}
+
+func (d *$name) FollowUp() string {
+	return \"$1 part 2 answer for $2\"
+}
+" >> $1/main.go
+
+# Create file for the day
+echo "package $1
+import (
+	\"bufio\"
+	\"os\"
+)
+
+type $2 struct {
+  input []string
+}
+
+func ($abbr *$2) load(filename string) error {
+	file, err := os.Open(filename)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+    $abbr.input = append($abbr.input, scanner.Text())
+	}
+	return nil
+}
+" >> $1/$2.go
+
+# Create the test file
+echo "package $1
+
+import \"testing\"
+
+func Test_read(t *testing.T) {
+	$abbr := $2{}
+	if err := $abbr.load(\"test_input.txt\"); err != nil {
+		t.Log(err)
+		t.FailNow()
+	}
+
+	if len($abbr.input) != 1000 {
+		t.Logf(\"Expected 1000 inputs, found %d\", len($abbr.input))
+		t.Fail()
+	}
+
+}
+" >> $1/$2_test.go
+
+# Create files for test input
+touch $1/test_input.txt
+touch $1/input.txt
+
+# Append Solution to Readme
+
+echo "
+### Day $1
+
+\`\`\`sh
+$ ./aoc2021 --$1
+The solution for \"$1\" is:
+$1 part 1 answer for $2
+$1 part 2 answer for $2
+\`\`\`
+" >> README.md