fix: update default preamble value and add TX power configuration for Seeed T1000-E variant

Author: MichTronics

README.md

@@ -201,7 +201,7 @@ Monitor at 115200 baud:
 ~/.platformio/penv/bin/pio device monitor
 ```
 
-Default air parameters: **869.480 MHz · SF8 · BW 62.5 kHz (`RF_BANDWIDTH_HZ=62500`) · CR 4/8 · preamble 8**
+Default air parameters: **869.480 MHz · SF8 · BW 62.5 kHz (`RF_BANDWIDTH_HZ=62500`) · CR 4/8 · preamble 16**
 Override at build time: `build_flags = -DRIVR_RF_FREQ_HZ=915000000`
 
 See [docs/FLASHING.md](docs/FLASHING.md) for all board variants and wiring tables.

variants/seeed_t1000_e/platformio.ini

@@ -18,6 +18,7 @@ build_flags =
     -DRF_SPREADING_FACTOR=8
     -DRF_BANDWIDTH_HZ=62500
     -DRF_CODING_RATE=8
+    -DRF_TX_POWER_DBM=22
     -DRIVR_RF_FREQ_HZ=869480000
 
 [env_t1000_e_base]