Add the readrom binary

The readrom binary is similar to `readelf` from Linux and it will allow
to display information from an NES/Famicom ROM file. For now the
information being shown is just the header, but in the future we might
also include disassembling parts of the code, or retrieving the "CHARS"
section for a given ROM file, and similar.

In order to implement the header parsing part a new library has been
introduced, simply named "header" which abstracts everything away so you
just need to call `Header::try_from("my bytes")` to fetch the actual
information.

Signed-off-by: Miquel Sabaté Solà <mikisabate@gmail.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/README.md b/README.md
index 4a74a66..6d99cd4 100644
--- a/README.md
+++ b/README.md
@@ -19,3 +19,10 @@ changed with the `-c/--configuration` flag, which accepts the following values:
   `CODE`, `VECTORS`, and `CHARS`.
 - `nrom65`: same as `nrom` but it also has `STARTUP` for compatibility with the
   default linker configuration from [cc65](https://github.com/cc65/cc65).
+
+## `readrom`
+
+The `readrom` reads a given ROM file and shows all the information that can be
+gathered from it. For now this only applies to information on the header, but in
+the future we might want to add disassembling user-specified segments, for
+example.