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_file_va.c

@@ -0,0 +1,43 @@
+#define KERNAUX_ACCESS_PROTECTED
+
+#include <kernaux/generic/file.h>
+#include <kernaux/printf.h>
+
+#include <assert.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define BUFFER_SIZE 1024
+
+static char buffer[BUFFER_SIZE];
+static size_t buffer_index = 0;
+
+static int my_putc(__attribute__((unused)) void *const file, unsigned char c)
+{
+    if (buffer_index >= BUFFER_SIZE) abort();
+    buffer[buffer_index++] = c;
+    return 1;
+}
+
+static const struct KernAux_File file = {
+    .putc = my_putc,
+    .puts = NULL,
+    .write = NULL,
+};
+
+static int my_printf(const char *const format, ...)
+{
+    va_list va;
+    va_start(va, format);
+    const int result = kernaux_vfprintf(&file, format, va);
+    va_end(va);
+    return result;
+}
+
+void example_main()
+{
+    const int result = my_printf("Hello, %s! Session ID: %u.", "Alex", 123);
+    assert((size_t)result == strlen(buffer));
+    assert(strcmp(buffer, "Hello, Alex! Session ID: 123.") == 0);
+}