docs: update README

README.md

@@ -6,7 +6,7 @@ to saved Wi-Fi credentials or starts a fallback provisioning access point.
 
 ## Prerequisites
 
-- PlatformIO Core installed at `/home/sasa/.platformio/penv/bin/pio`;
+- PlatformIO Core installed at `$HOME/.platformio/penv/bin/pio`;
 - a C11 host compiler available as `cc`;
 - Python 3.
 
@@ -15,7 +15,7 @@ to saved Wi-Fi credentials or starts a fallback provisioning access point.
 Parse the locked PlatformIO configuration:
 
 ```sh
-/home/sasa/.platformio/penv/bin/pio project config
+$HOME/.platformio/penv/bin/pio project config
 ```
 
 Run the portable host tests and deterministic asset check:
@@ -28,13 +28,13 @@ Build the firmware. The PlatformIO hook checks the application image against
 the 2 MiB `factory` partition:
 
 ```sh
-/home/sasa/.platformio/penv/bin/pio run
+$HOME/.platformio/penv/bin/pio run
 ```
 
 Generate compressed assets explicitly when needed:
 
 ```sh
-/home/sasa/.platformio/penv/bin/python scripts/generate_web_assets.py
+$HOME/.platformio/penv/bin/python scripts/generate_web_assets.py
 ```
 
 Build the LittleFS image. Asset generation runs automatically before packaging,
@@ -42,7 +42,7 @@ and the PlatformIO hook checks the image against the 1,984 KiB `littlefs`
 partition:
 
 ```sh
-/home/sasa/.platformio/penv/bin/pio run --target buildfs
+$HOME/.platformio/penv/bin/pio run --target buildfs
 ```
 
 ## Device commands
@@ -50,14 +50,14 @@ partition:
 Upload the application and LittleFS image:
 
 ```sh
-/home/sasa/.platformio/penv/bin/pio run --target upload
-/home/sasa/.platformio/penv/bin/pio run --target uploadfs
+$HOME$/.platformio/penv/bin/pio run --target upload
+$HOME$/.platformio/penv/bin/pio run --target uploadfs
 ```
 
 Monitor startup at 115200 baud:
 
 ```sh
-/home/sasa/.platformio/penv/bin/pio device monitor
+$HOME/.platformio/penv/bin/pio device monitor
 ```
 
 A successful boot reports the firmware version, LittleFS capacity and use,
@@ -90,8 +90,8 @@ SSID, refuses to overwrite unexpected saved credentials, and clears its test
 record after verifying fallback recovery:
 
 ```sh
-/home/sasa/.platformio/penv/bin/pio run -e milestone-003-device-test
-/home/sasa/.platformio/penv/bin/pio run -e milestone-003-device-test --target upload
+$HOME/.platformio/penv/bin/pio run -e milestone-003-device-test
+$HOME/.platformio/penv/bin/pio run -e milestone-003-device-test --target upload
 ```
 
 Restore the normal firmware afterward with the standard upload command.