Restructure README around the metadata-to-GRDM workflow

Author: yacchin1205

README.md

@@ -1,15 +1,51 @@
-# getmetadata
+# RDM-metadata-cli
 
-Extract metadata from local files for GRDM (GakuNin RDM).
+Extract metadata from local files and register it to GakuNin RDM (GRDM).
+The data itself never leaves confidential storage; only its metadata is
+published, so the data stays private while remaining findable.
 
 ## Installation
 
+### Prebuilt binaries
+
+Download from the
+[Releases page](https://github.com/RCOSDP/RDM-metadata-cli/releases).
+`ggwave` ships as a separate archive — see [ggwave](#ggwave).
+
+### Build from source
+
 ```bash
 go build -o getmetadata ./cmd/getmetadata
 go build -o grdm ./cmd/grdm
 ```
 
-## Usage
+## Example
+
+Extract metadata on the data machine, carry it to a networked machine, and
+register it to GRDM:
+
+```
+getmetadata ──> ggwave ──(audio)──> ggwave ──> grdm ──> GRDM
+ (data host)                                  (networked host)
+```
+
+```bash
+# Data host (offline): extract and transmit
+getmetadata -format mebyo-project ./data | ggwave send
+
+# Networked host: receive and register
+ggwave recv | grdm metadata create -project <id> -schema <name>
+```
+
+When the data host has a network path, pipe directly without `ggwave`:
+
+```bash
+getmetadata -format mebyo-project ./data | grdm metadata create -project <id> -schema <name>
+```
+
+## getmetadata
+
+Scans a directory and writes metadata as JSON to stdout.
 
 ```bash
 getmetadata -format <format> <directory>
@@ -31,63 +67,35 @@ getmetadata -format <format> <directory>
 | Text | csv, tsv, txt | number-of-rows, number-of-columns, delimiter, character-code |
 | Excel | xlsx, xlsm | number-of-rows, number-of-columns |
 
-## Examples
+## ggwave
 
-```bash
-# List files with metadata
-getmetadata -format list ./data
-
-# Generate project metadata for Mebyo DB
-getmetadata -format mebyo-project ./data
-
-# Generate file metadata for Mebyo DB
-getmetadata -format mebyo-file ./data
-```
-
-### With grdm CLI
-
-```bash
-# Create project metadata
-getmetadata -format mebyo-project ./data | \
-  grdm metadata create -project <id> -schema <schema-name>
-
-# Bulk update file metadata
-getmetadata -format mebyo-file ./data | \
-  grdm file bulk update -project <id> -schema <schema-name> osfstorage
-```
-
-## ggwave CLI
+Transfers JSON metadata between machines over sound (speaker to microphone),
+for a data host that has no network path — the [Example](#example) above uses it
+as the bridge.
 
-Transfer metadata between machines via audio (speaker/microphone) using [ggwave](https://github.com/ggerganov/ggwave).
+### Prebuilt binary
 
-### Prerequisites
+Download from the
+[Releases page](https://github.com/RCOSDP/RDM-metadata-cli/releases)
+(`linux-amd64`, `darwin-arm64`, `windows-amd64`).
 
-- [ggwave](https://github.com/ggerganov/ggwave) installed (`cmake && make && make install`)
-- [PortAudio](http://www.portaudio.com/) installed (`brew install portaudio` on macOS)
-- `CGO_ENABLED=1`
+### Build from source
 
-### Build
+Needs the native ggwave and PortAudio libraries:
 
 ```bash
 CGO_ENABLED=1 go build -o ggwave ./cmd/ggwave
 ```
 
-### Usage
+See [docs/ggwave.md](docs/ggwave.md) for the protocol and build details.
 
-```bash
-# Send metadata via speaker
-getmetadata -format mebyo-project ./data | ggwave send
+## grdm
 
-# Receive metadata via microphone
-ggwave recv | grdm metadata create -project <id> -schema <name>
+Registers metadata to GRDM and reads/writes project files through its API.
 
-# File-based (for testing)
-echo '{"title":"test"}' | ggwave send -out test.wav
-ggwave recv -in test.wav
+```bash
+getmetadata -format mebyo-file ./data | \
+  grdm file bulk update -project <id> -schema <name> osfstorage
 ```
 
-See [docs/ggwave.md](docs/ggwave.md) for technical details.
-
-## grdm CLI
-
-See [docs/grdm.md](docs/grdm.md) for the GRDM API client documentation.
+See [docs/grdm.md](docs/grdm.md) for configuration and the full command list.