A lot of time using nano needs to have features to keep the cursor position and configure space sizes. It’s easy to configure user profile settings for nano that located in ~/.nanorc

Use any text editor and edit file .nanorc that located in the home directory

For example nano ~/.nanorc

Add the next lines:

set positionlog
set tabsize 4
set tabstospaces
set autoindent

Description:
set positionlog - for remember position
set tabsize 4 - set tab size
set tabstospaces - just convert tabs to spaces
set autoindent - new lines will contain same amount of spaces

More parameters can find on page nano-editor.org