Expand README and fix a few flaws

Author: savannstm

README.md

@@ -1,7 +1,7 @@
 # rpgm-archive-decrypter
 
-RPGM Archive Decrypter is a [RPG Maker Decrypter](github.com/uuksu/rpgmakerdecrypter) rewrite in Rust (**_BLAZINGLY FAST_** :fire:).
-It can be used to extract encrypted archives of RPG Maker XP/VX/VXAce game engines, and generate project files for decrypted data.
+RPGM Archive Decrypter is a [RPG Maker Decrypter](https://github.com/uuksu/rpgmakerdecrypter) rewrite in Rust (**_BLAZINGLY FAST_** :fire:).
+It can be used to extract encrypted archives of RPG Maker XP/VX/VXAce game engines.
 It is faster and lighter than RPG Maker Decrypter, and also has **NO** requirements to run, except a working PC.
 
 _And also features much more cleaner code!_
@@ -13,10 +13,22 @@ One with `.exe` extension is for Windows, without it - is for Linux.
 
 ## Usage
 
-Call `rpgmad.exe -h` for help.
+Call `rpgmad -h` for help.
 
 ```text
-
+A tool to extract encrypted .rgss RPG Maker archives.
+
+Usage: rpgmad.exe [OPTIONS]
+
+Options:
+  -i, --input-file <input-path>
+          Path to the RGSSAD file. [default: ./]
+  -o, --output-dir <output-path>
+          Path to put output files. [default: ./]
+  -f, --force
+          Forcefully overwrite existing Data, Graphics and other files.
+  -h, --help
+          Prints the help message.
 ```
 
 For example, to extract archive to same same directory where it exists:
@@ -26,13 +38,24 @@ You can recongnize archives by their extensions: `rgssad`, `rgss2a`, `rgss3a`.
 
 ## GUI
 
-Full-featured GTK GUI built with `gtk-rs` is in progress.
+Full-featured GUI will maybe come out someday. Not sure in a relevancy.
+
+## Development
 
-## Building
+### Building
 
 Requirements: `rustup` with installed Rust toolchain, linker (`gcc`, `llvm` or `msvc`).
 
-Clone the repository with `git` and compile with `cargo b -r`.
+Clone the repository and compile with `cargo b -r`.
+
+### Tests
+
+I'm not really skilled in tests, but the validity of output files is tested the following ways:
+
+-   Of images, using image viewers.
+-   Of rx/rvdata files, using [rvpacker-txt-rs](https://github.com/savannstm/rvpacker-txt-rs).
+
+As long as these tests succesful, there shouldn't be any bugs.
 
 ## License