readmes: update supported ESP-IDF version to 5.1.1

Update README instructions to match latest supported version of ESP-IDF

Signed-off-by: Sam Friedman <sam@golioth.io>

README.md

@@ -137,7 +137,7 @@ The `verify.py` script will return 0 on success (all tests pass), and non-zero o
 
 | Board               | Platform             | Module           | Last Tested Commit    |
 | ---                 | ---                  | ---              | ---                   |
-| ESP32-S3-DevKitC-1  | ESP-IDF (v5.0)       | ESP32-S3-WROOM-1 | Every commit, CI/CD   |
-| ESP32-DevKitC-32E   | ESP-IDF (v5.0)       | ESP32-WROOM-32E  | v0.7.0 (Jun 15, 2023) |
-| ESP32-C3-DevKitM-1  | ESP-IDF (v5.0)       | ESP32-C3-MINI-1  | v0.7.0 (Jun 15, 2023) |
+| ESP32-S3-DevKitC-1  | ESP-IDF (v5.1.1)     | ESP32-S3-WROOM-1 | Every commit, CI/CD   |
+| ESP32-DevKitC-32E   | ESP-IDF (v5.1.1)     | ESP32-WROOM-32E  | v0.7.0 (Jun 15, 2023) |
+| ESP32-C3-DevKitM-1  | ESP-IDF (v5.1.1)     | ESP32-C3-MINI-1  | v0.7.0 (Jun 15, 2023) |
 | CY8CPROTO-062-4343W | ModusToolbox (3.0.0) | PSoC® 6 CYW4343W | v0.7.0 (Jun 15, 2023) |

examples/esp_idf/README.md

@@ -2,11 +2,11 @@
 
 This repo contains a set of examples intended to build
 and run in the latest release of esp-idf
-(currently [5.0](https://github.com/espressif/esp-idf/releases/tag/v5.0)).
+(currently [5.1.1](https://github.com/espressif/esp-idf/releases/tag/v5.1.1)).
 
 ### Install esp-idf
 
-Install version 5.0 of esp-idf using the
+Install version 5.1.1 of esp-idf using the
 [installation directions from Espressif](https://docs.espressif.com/projects/esp-idf/en/latest/esp32/get-started/index.html#installation).
 This is the version of esp-idf this SDK is tested against.
 
@@ -16,7 +16,7 @@ For Linux users, you can install esp-idf with these commands:
 sudo apt-get install git wget flex bison gperf python3 python3-venv cmake ninja-build ccache libffi-dev libssl-dev dfu-util libusb-1.0-0
 mkdir -p ~/esp
 cd ~/esp
-git clone --recursive https://github.com/espressif/esp-idf.git -b v5.0
+git clone --recursive https://github.com/espressif/esp-idf.git -b v5.1.1
 cd esp-idf
 ./install.sh all
 ```