feat(392-is-subsequence): simplify and add golang soln

0392_is-subsequence/golang/main.go

@@ -0,0 +1,21 @@
+func isSubsequence(s string, t string) bool {
+	slen, tlen, si, ti := len(s), len(t), 0, 0
+
+	if slen == 0 {
+		return true
+	}
+
+	if slen > tlen {
+		return false
+	}
+
+	for ti < tlen && si < slen {
+		if s[si] == t[ti] {
+			si += 1
+		}
+
+		ti += 1
+	}
+
+	return si == slen
+}