Initial commit: Simple Sensor firmware for Heltec T114 with BME280

- MeshCore-based Simple Sensor firmware
- Heltec T114 without display
- BME280 sensor support (temp/humidity/pressure)
- Radio: 868.856018 MHz, SF7, BW62.5 kHz, CR4/7
- 2-byte path hash
- PlatformIO project

boards/rak3172.json

@@ -0,0 +1,33 @@
+{
+  "build": {
+    "arduino": {
+      "variant_h": "variant_RAK3172_MODULE.h"
+    },
+    "core": "stm32",
+    "cpu": "cortex-m4",
+    "extra_flags": "-DSTM32WL -DSTM32WLxx -DSTM32WLE5xx",
+    "framework_extra_flags": {
+      "arduino": "-DUSE_CM4_STARTUP_FILE -DARDUINO_RAK3172_MODULE"
+    },
+    "f_cpu": "48000000L",
+    "mcu": "stm32wle5ccu",
+    "product_line": "STM32WLE5xx",
+    "variant": "STM32WLxx/WL54CCU_WL55CCU_WLE4C(8-B-C)U_WLE5C(8-B-C)U"
+  },
+  "debug": {
+    "default_tools": ["stlink"],
+    "jlink_device": "STM32WLE5CC",
+    "openocd_target": "stm32wlx",
+    "svd_path": "STM32WLE5_CM4.svd"
+  },
+  "frameworks": ["arduino"],
+  "name": "BB-STM32WL",
+  "upload": {
+    "maximum_ram_size": 65536,
+    "maximum_size": 262144,
+    "protocol": "stlink",
+    "protocols": ["stlink", "jlink"]
+  },
+  "url": "https://store.rakwireless.com/products/wisduo-lpwan-module-rak3172",
+  "vendor": "RAK"
+}