feat: add Linux build guide and enhance make_config.yaml with detailed description and features

docs/linux_build_guide.md

@@ -0,0 +1,45 @@
+# Linux Build Guide
+
+## Determining Package Size
+To determine the installed size for your Linux package configuration, you can use the following script:
+
+```bash
+#!/bin/bash
+
+# Build the Linux app
+flutter build linux
+
+# Get size in KB and add 17% buffer for runtime dependencies
+SIZE_KB=$(du -sk build/linux/x64/release/bundle | cut -f1)
+BUFFER_SIZE_KB=$(($SIZE_KB + ($SIZE_KB * 17 / 100)))
+
+echo "Actual bundle size: $SIZE_KB KB"
+echo "Recommended installed_size (with 17% buffer): $BUFFER_SIZE_KB KB"
+```
+
+Save this as `get_package_size.sh` in your project root and make it executable:
+```bash
+chmod +x get_package_size.sh
+```
+
+### Usage
+1. Run the script:
+   ```bash
+   ./get_package_size.sh
+   ```
+2. Use the output value for `installed_size` in your `linux/packaging/deb/make_config.yaml` file:
+   ```yaml
+   installed_size: 75700  # Replace with the value from the script
+   ```
+
+### Why add a buffer?
+The 17% buffer is added to account for:
+- Runtime dependencies
+- Future updates
+- Potential additional assets
+- Prevent installation issues on systems with limited space
+
+### Notes
+- The installed size should be specified in kilobytes (KB)
+- Always round up the buffer size to be safe
+- Re-run this script after significant changes to your app (new assets, dependencies, etc.)