Initial solution to exercise gopalindrome

src/gopalindrome/go.mod

+module github.com/turngeek/examples-go/src/gopalindrome
+
+go 1.16

src/gopalindrome/main.go

+package main
+
+import (
+	"fmt"
+	"os"
+	"strings"
+	"unicode"
+)
+
+func main() {
+	if len(os.Args) < 2 {
+		fmt.Println("Usage: gopalindrome [sentence]")
+	} else {
+		sentence := strings.Join(os.Args[1:], " ")
+		var result string
+		if isPalindrome := isPalindrome(sentence); isPalindrome {
+			result = "a"
+		} else {
+			result = "not a"
+		}
+		fmt.Printf("Your sentence: '%s' is %s palindrome!\n", sentence, result)
+	}
+}
+
+func isPalindrome(s string) bool {
+	var letters []rune
+	for _, r := range s {
+		if unicode.IsLetter(r) {
+			letters = append(letters, unicode.ToLower(r))
+		}
+	}
+	for i := range letters {
+		if letters[i] != letters[len(letters)-1-i] {
+			return false
+		}
+	}
+	return true
+}