I've just followed the instructions at 

https://support.google.com/mail/answer/9212652?co=GENIE.Platform%3DiOS&oco=1 and sent feedback about this to Google.

The difference seems to be that when you copy the selection in the Notes app, it puts the text onto the clipboard in two formats: plain text and HTML. The Gmail app then pastes the HTML which includes <br> tags for line breaks.

Textastic only puts the selection in plain text format onto the clipboard (like most text editors). 

The Gmail app's mail composer doesn't handle plain text correctly and doesn't insert <br> tags when it encounters new line characters in plain text.

This is a bug in the Gmail app.

I can reproduce it when copying text from these other apps and pasting it into a new email in Gmail as well:

• iA Writer
• 1Writer
• GoCoEdit
• Runestone

You can upload any type of file using the file transfer screen:
https://www.textasticapp.com/v10/manual/remote_servers/remote_file_transfer_screen.html

Hello, Textastic only supports ".tmTheme" files. ".sublime-color-scheme" files are a completely different file format that is not currently supported.

I'll consider adding support for .sublime-color-scheme" files in a future update.

You can find an online editor for .tmTheme files at https://tmtheme-editor.glitch.me/ 

It has a huge gallery of themes you can download and also includes a "Gruvbox" theme (but not Gruvbox Dark Hard).

Thanks a lot for the details. I’ll look into it. 

Which syntax definition or type of file are you using?

You can find a character count and word count in the file properties. See https://www.textasticapp.com/v10/manual/viewing_editing_files/file_properties.html

But, this is for the whole document, not for the selected text.

Thanks, I'll take a look!

Sounds useful. Which editors do you know that have this feature?