Updates build script.

Author: kdschlosser

README.md

@@ -570,18 +570,65 @@ Common options that are available across all esp32 targets:
 * `--task-stack-size={stack size in bytes}`: Sets the default stack size for threads
 * `CONFIG_*={value}`: You can alter the config settings of the esp-idf by using these settings. Refer to the ESP-IDF documentation
                       for further information
+* `--uart-repl-bitrate={baud/bitrate}`: This changes the connection speed for the serial connection when using the UART REPL.
+                                        This is a nice feature to use when transferring large files to the ESP32. The highest 
+                                        speed I have been able to set it to is 921600, you might be able to set it higher depending
+                                        on the UART to USB bridge IC used and the type of physical connection. 
+* `--enable-uart-repl={y/n}`: This allows you to turn on and off the UART based REPL. You will wany to set this of you use USB-CDC or JTAG for the REPL output
 
 
 Options specific to the ESP32-S3 processors:
 
-* `--usb-otg`: Enable REPL output on pins 19 & 20 of the ESP32-S3
-* `--usb-jtag`: Enable JTAG output on pins 19 & 20 of the ESP32-S3
 * `--octal-flash`: Set this if you have octal SPI flash
 
-Options specific to the ESP32-S2 processors:
+Options specific to the ESP32-S2, ESP32-S3, ESP32-C3 and ESP32-C6 processors:
 
-* `--usb-otg`: Enable REPL output on pins 19 & 20 of the ESP32-S2
-* `--usb-jtag`: Enable JTAG output on pins 19 & 20 of the ESP32-S2
+* `--enable-cdc-repl={y/n}`: Enable/disable REPL output over CDC on the USB pins
+* `--enable-jtag-repl={y/n}`: Enable/disable REPL output over JTAG on the USB pins
+
+
+This next option is abailable for all ESP32 series MCU's I placed it here instead of above 
+because it is going to need some in depth explaining. This is for advanced users.
+
+* `--custom-board-path`
+
+I added the ability to provide a path to a custom board. There are a few requirememnts for 
+this to work properly. The path needs to point to the folder that holds the board specification 
+files. Here is a list of required files.
+
+* `board.json`: This file outlines what the board is. At a minimum the file needs to contain the following.
+                ```
+                {
+                    "mcu": "{MCU}"
+                }
+                ```
+                where `{MCU}` is one of the follwing:
+
+  * esp32
+  * esp32s2
+  * exp32s3
+  * exp32c3
+  * exp32c6
+
+* `sdkconfig.board`: This file contains all of the ESP-IDF specific config settings. If you don't know 
+                     what needs to be set in here then please ask me for assistance.
+* `mpconfigboard.h`: MicroPython config settings. If you don't know what needs to be set in here then
+                     please ask me for assistance.
+* `mpconfigboard.cmake`: Build script. At a minimum the following should be in the build script.
+                         `{MCU}` is replaced with one of the options from the list of MCU's above.
+                         `{BOARD_CONATINING_FOLDER}` if the name of the folder these files are located in.
+```
+set(IDF_TARGET {MCU})
+
+set(SDKCONFIG_DEFAULTS
+    boards/sdkconfig.base
+    ${SDKCONFIG_IDF_VERSION_SPECIFIC}
+    boards/{BOARD_CONATINING_FOLDER}/sdkconfig.board
+)
+```
+
+* `partition.csv`: This file dictates what the partitions are supposed to be on the ESP32. As for assistance
+                   If you do not know how to create one of these.
 
 <br>