Maintenance (#98)

* Fix copyright
* Remove thanks
* Update CONTRIBUTING.md
* Remove bitfields from struct KernAux_Arch_I386_TSS
* Change description of package "mbr"
* Make generic file stable
* Rename printf examples

examples/printf_str.c

@@ -0,0 +1,21 @@
+#include <kernaux/printf.h>
+
+#include <assert.h>
+#include <string.h>
+
+#define BUFFER_SIZE 1024
+
+static char buffer[BUFFER_SIZE];
+
+void example_main()
+{
+    const int result = kernaux_snprintf(
+        buffer,
+        sizeof(buffer),
+        "Hello, %s! Session ID: %u.",
+        "Alex",
+        123
+    );
+    assert((size_t)result == strlen(buffer));
+    assert(strcmp(buffer, "Hello, Alex! Session ID: 123.") == 0);
+}