Add build stamp (#56)

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## Description
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Make sure that a menu build is identifiable.

## Motivation and Context
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It is not always obvious what version of a menu is running.
In future, the build date should be used as the start time for carts
that do not have a RTC.

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Works on the SC64, although I am sure it can be improved.

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## Types of changes
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- [x] Improvement (non-breaking change that adds a new feature)
- [ ] Bug fix (fixes an issue)
- [ ] Breaking change (breaking change)
- [ ] Config and build (change in the configuration and build system,
has no impact on code or features)

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- [ ] All new and existing tests passed.

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Makefile

@@ -7,6 +7,8 @@ ASSETS_DIR = assets
 BUILD_DIR = build
 OUTPUT_DIR = output
 
+FLAGS += -DMENU_VERSION=\"0.0.1.$(shell date +%Y-%m-%dT%H:%M:%SZ).ALPHA\"
+
 include $(N64_INST)/include/n64.mk
 
 N64_CFLAGS += -iquote $(SOURCE_DIR) -iquote $(ASSETS_DIR) -I $(SOURCE_DIR)/libs -flto=auto $(FLAGS)

src/menu/views/credits.c

@@ -2,7 +2,7 @@
 
 
 #ifndef MENU_VERSION
-#define MENU_VERSION "0.0.0.5.ALPHA"
+#define MENU_VERSION "0.0.0.6.ALPHA"
 #endif