README: Add version-specific links

Make it clearer how the README fits in with the docs.

README.md

@@ -4,22 +4,27 @@
 
 ESP-IDF is the official development framework for the [ESP32](https://espressif.com/en/products/hardware/esp32/overview) chip.
 
-# Developing With the ESP-IDF
+# Developing With ESP-IDF
 
 ## Setting Up ESP-IDF
 
 See setup guides for detailed instructions to set up the ESP-IDF:
 
-* [Windows Setup Guide](https://docs.espressif.com/projects/esp-idf/en/latest/get-started/windows-setup.html)
-* [Mac OS Setup Guide](https://docs.espressif.com/projects/esp-idf/en/latest/get-started/macos-setup.html)
-* [Linux Setup Guide](https://docs.espressif.com/projects/esp-idf/en/latest/get-started/linux-setup.html)
+* [Getting Started Guide for the stable ESP-IDF version](https://docs.espressif.com/projects/esp-idf/en/stable/get-started/)
+* [Getting Started Guide for the latest (master branch) ESP-IDF version](https://docs.espressif.com/projects/esp-idf/en/latest/get-started/)
 
 ## Finding a Project
 
-As well as the [esp-idf-template](https://github.com/espressif/esp-idf-template) project mentioned in the setup guide, ESP-IDF comes with some example projects in the [examples](examples) directory.
+As well as the [esp-idf-template](https://github.com/espressif/esp-idf-template) project mentioned in Getting Started, ESP-IDF comes with some example projects in the [examples](examples) directory.
 
 Once you've found the project you want to work with, change to its directory and you can configure and build it.
 
+To start your own project based on an example, copy the example project directory outside of the ESP-IDF directory.
+
+# Quick Reference
+
+See the Getting Started guide links above for a detailed setup guide. This is a quick reference for common commands when working with ESP-IDF projects:
+
 ## Configuring the Project
 
 `make menuconfig`
@@ -36,15 +41,17 @@ Once done configuring, press Escape multiple times to exit and say "Yes" to save
 
 ## Compiling the Project
 
-`make all`
+`make -j4 all`
 
 ... will compile app, bootloader and generate a partition table based on the config.
 
+NOTE: The `-j4` option causes `make` to run 4 parallel jobs. This is much faster than the default single job. The recommended number to pass to this option is `-j(number of CPUs + 1)`.
+
 ## Flashing the Project
 
 When `make all` finishes, it will print a command line to use esptool.py to flash the chip. However you can also do this from make by running:
 
-`make flash`
+`make -j4 flash`
 
 This will flash the entire project (app, bootloader and partition table) to a new chip. The settings for serial port flashing can be configured with `make menuconfig`.
 
@@ -56,24 +63,24 @@ The `make monitor` target uses the [idf_monitor tool](https://docs.espressif.com
 
 Exit the monitor by typing Ctrl-].
 
-To flash and monitor output in one pass, you can run:
+To build, flash and monitor output in one pass, you can run:
 
-`make flash monitor`
+`make -j4 flash monitor`
 
-## Compiling & Flashing Just the App
+## Compiling & Flashing Only the App
 
 After the initial flash, you may just want to build and flash just your app, not the bootloader and partition table:
 
 * `make app` - build just the app.
 * `make app-flash` - flash just the app.
 
-`make app-flash` will automatically rebuild the app if it needs it.
+`make app-flash` will automatically rebuild the app if any source files have changed.
 
 (In normal development there's no downside to reflashing the bootloader and partition table each time, if they haven't changed.)
 
 ## Parallel Builds
 
-ESP-IDF supports compiling multiple files in parallel, so all of the above commands can be run as `make -jN` where `N` is the number of parallel make processes to run (generally N should be equal to or one more than the number of CPU cores in your system.)
+ESP-IDF supports compiling multiple files in parallel, so all of the above commands can be run as `make -jN` where `N` is the number of parallel make processes to run (generally N should be equal to the number of CPU cores in your system, plus one.)
 
 Multiple make functions can be combined into one. For example: to build the app & bootloader using 5 jobs in parallel, then flash everything, and then display serial output from the ESP32 run: