Update docs to provide more details

doc/docker_build.md

@@ -2,22 +2,50 @@
 # Building in Docker
 
 ### Prerequisities
-- only Docker
+- Linux platform
+- Docker
+- Repository clone (refer to [README.md](/README.md))
 
-No need to install ESP-IDF or anything else. All commands should be run in a project root.
+No need to install ESP-IDF or anything else. All commands should be run in project root folder.
 
-
-## menuconfig
+## Configure, Build and Flash
+### Start an interactive IDF environnement
+In this interactive shell you can run menuconfig, build, flash and monitor command. 
 ```
-docker run --rm -it -v .:/project -w /project espressif/idf:v4.3.1 idf.py menuconfig
+docker run --rm -it -v .:/project -w /project -v /dev:/dev --privileged espressif/idf:v4.3.5
 ```
 
-## Build
+### Configure
+Then in your docker interactive shell, start by configuring for your platform. More info about the config in [README.md](/README.md#config).
 ```
-docker run --rm -it -v .:/project -w /project espressif/idf:v4.3.1 idf.py build
+idf.py menuconfig
+```
+Save with `<s>` and exit with `<q>`.
+
+### Build, flash and monitor:
+```
+idf.py build flash monitor
+```
+<span style="color: orange">If idf.py can't access to USB devices, try to restart your docker interactive shell in sudo.</span>
+
+### Exit
+Exit IDF monitor mode: `<Ctrl+]>`
+
+Exit docker interactive shell: `exit`
+
+## Specific actions
+If you want to execute a specific command or to generate a reusable .bin file. 
+### menuconfig
+```
+docker run --rm -it -v .:/project -w /project espressif/idf:v4.3.5 idf.py menuconfig
 ```
 
-## Flash
+### Build
+```
+docker run --rm -it -v .:/project -w /project espressif/idf:v4.3.5 idf.py build
+```
+
+### Flash
 Mapping of serial port to container is not simple in windows but you can merge all generated `bin` files into single firmware and flash the firmware manually using some windows tool.
  - [ESP Tool web flasher](https://espressif.github.io/esptool-js/)
  - [ESP32 Flash Download tool](https://www.espressif.com/en/support/download/other-tools)
@@ -42,6 +70,8 @@ docker run
     -it                             // runs interactive terminal
     -v .:/project                   // maps current directory to /project in container
     -w /project                     // sets working directory inside a container to /project
+    -v /dev:/dev                    // maps devices directory to acces USB and Serial devices inside docker
+    --privileged                    // grants docker rights to acces host devices
     espressif/idf:v4.3.5            // image name + version
     idf.py menuconfig               // run menuconfig
 ```