layout fix (#1845)

(removed quotes from last line, and fixed indentation, no text changes)

Author: lynxzp

docs/arduino-ide/debian_ubuntu.md

@@ -24,12 +24,13 @@ Installation instructions for Debian / Ubuntu OS
 
 - If you have Arduino installed to ~/, modify the installation as follows, beginning at `mkdir -p ~/Arduino/hardware`:
 
-```bash
+  ```bash
   cd ~/Arduino/hardware
   mkdir -p espressif && \
   cd espressif && \
   git clone https://github.com/espressif/arduino-esp32.git esp32 && \
   cd esp32 && \
   git submodule update --init --recursive && \
   cd tools && \
-  python2 get.py```
+  python2 get.py
+  ```