feat: add day1 part 1 solution

internal/2015/DayOne/code.go

@@ -0,0 +1,32 @@
+package dayone
+
+import (
+	"advent-of-code/internal/registry"
+	"os"
+)
+
+func init() {
+	registry.Register("2015D1", ParseInput, PartOne, PartTwo)
+}
+
+func ParseInput(filepath string) string {
+	content, _ := os.ReadFile(filepath)
+	return string(content)
+}
+
+func PartOne(data string) int {
+	floor := 0
+	for _, char := range data {
+		switch char {
+		case '(':
+			floor++
+		case ')':
+			floor--
+		}
+	}
+	return floor
+}
+
+func PartTwo(data string) int {
+	return 0
+}