[DOCS] Migrate documentation from VuePress 1.x to VitePress (#2299)

- Replace VuePress 1.9.10 with VitePress 1.6.4
- Convert config from CommonJS to ESM TypeScript (config.mts)
- Convert shared Theengs nav config to ESM (commonConfig.mts)
- Rewrite BoardEnvironmentTable in Vue 3 Composition API
- Rewrite FlashEnvironmentSelector in Vue 3 Composition API
- Enable built-in local search and dark mode
- Add medium-zoom for image zoom
- Use VitePress CSS variables for dark mode compatibility
- Update CI script paths from .vuepress to .vitepress
- Update .gitignore for VitePress build artifacts
- Rename README.md files to index.md (VitePress convention)
- Fix markdown compatibility (angle-bracket escaping, image paths)
- Drop PWA plugin (not needed)

Co-authored-by: Florian <1technophile@users.noreply.github.com>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docs/prerequisites/devices.md

@@ -8,9 +8,7 @@ Added to that is an overview of devices supported by OpenMQTTGateway:
 OpenMQTTGateway can support a wide range of 433mhz/315mhz devices, all the ones with SC5262 / SC5272, HX2262 / HX2272, PT2262 / PT2272, EV1527, RT1527, FP1527, HS1527 chipsets are supported by the RF gateway. Added to that RF2 support Kaku and Pilight an [huge list](https://wiki.pilight.org/devices). 
 Note that for the moment RF, RF2 and Pilight can not be activated on the same boards together.
 
-![boards](../img/OpenMQTTGateway_devices_rf1.png ':size=250%')
-![boards](../img/OpenMQTTGateway_devices_rf2.png ':size=250%')
-![boards](../img/OpenMQTTGateway_devices_rf3.png ':size=250%')
+
 
 ## For BLE devices 
 OpenMQTTGateway is able to scan all the BLE devices that advertise their data so as to do presence detection. 
@@ -23,8 +21,6 @@ OpenMQTTGateway currently supports the decoding of [more than 100 Bluetooth devi
 - (3) See https://github.com/pvvx/ATC_MiThermometer
 :::
 
-![devices](../img/OpenMQTTGateway_devices_ble.png ':size=250%')
-
 ## For infrared IR devices 
 The list of supported devices for ESP is [here](https://github.com/crankyoldgit/IRremoteESP8266/blob/master/SupportedProtocols.md), and [here](https://github.com/1technophile/OpenMQTTGateway/blob/6f73160d1421bebf2c1bbc9b8017978ff5b16520/main/config_IR.h#L123) for Arduino boards, as there is also the possibility of using raw and global cache (ESP) sending possibilities of this gateway is huge!