feat: move source files into retoor_c directory and add build echo messages

- Add echo messages for both build targets to indicate which project is being compiled
- Update isspam.c path to reflect new retoor_c/ subdirectory structure
- Keep binary output location unchanged at project root

retoor_c/rstr.h

@@ -0,0 +1,52 @@
+#ifndef RSTR_H
+#define RSTR_H
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+typedef struct str_t {
+    char *content;
+    size_t length;
+    size_t buffer_size;
+    size_t size;
+} str_t;
+
+str_t *strn(size_t buffer_size) {
+    str_t *result = (str_t *)malloc(sizeof(str_t));
+    result->length = 0;
+    result->size = buffer_size;
+    result->buffer_size = buffer_size;
+    result->content = (char *)malloc(buffer_size);
+    result->content[0] = 0;
+    return result;
+}
+void stra(str_t *str, const char *to_append) {
+    size_t required_new_length = str->length + strlen(to_append) + 1;
+    str->length += strlen(to_append);
+    if (required_new_length > str->size) {
+        str->size += required_new_length + str->buffer_size;
+        str->content = (char *)realloc(str->content, str->size + 1);
+    } else {
+        // printf("NO NDEED\n");
+    }
+    strcat(str->content, to_append);
+    str->content[str->length] = 0;
+}
+void strac(str_t *str, const char c) {
+    char to_append[] = {c, 0};
+    stra(str, to_append);
+}
+void strd(str_t *str) {
+    if (str->content) {
+        free(str->content);
+    }
+    free(str);
+}
+char *strc(str_t *str) {
+    char *content = str->content;
+    str->content = NULL;
+    strd(str);
+    return content;
+}
+
+#endif