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doc/EN/dev_guide/directories.md

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+# Directory Structure of Erg
+
+```console
+ └─┬ assets: images
+   ├─ CODE_OF_CONDUCT: Code of Conduct
+   ├─┬ compiler
+   │ ├─ erg_common: common utilities
+   │ ├─ erg_compiler: Compiler
+   │ └─ erg_parser: Parser
+   ├─┬ doc
+   │ ├─┬ EN
+   │ │ ├─ API: Erg standard API
+   │ │ ├─ compiler: about implementation of the compiler
+   │ │ ├─ dev_guide: guide for developers & contributors
+   │ │ ├─ python: Knowledge of Python required for Erg development
+   │ │ ├─ syntax: syntax of Erg
+   │ │ └─ tools: about Erg's CLI tools
+   │ └─ JA
+   ├─ examples: sample code
+   ├─ library: Erg libraries
+   ├─ src: main.rs & driver
+   └─ tests: test code
+```