* eat.el: Rename prompt mode to line mode, also rename related
symbols to have 'eat-line-' or 'eat--line-' prefix.
* eat.el (eat-enable-native-shell-prompt-editing): Rename to
'eat-enable-auto-line-mode'.
* eat.el (eat--line-mode-enter-auto)
(eat--line-mode-exit-auto): New function.
* eat.el (eat--post-prompt, eat--post-cont-prompt): Call
'eat--line-mode-enter-auto' to enter line mode.
* eat.el (eat--pre-cmd): Call 'eat--line-mode-exit-auto'.
* eat.el (eat--get-shell-history): Populate input ring
unconditionally.
* eat.el (eat-emacs-mode, eat-semi-char-mode, eat-char-mode):
Call 'eat--line-mode-exit' to exit line mode.
* eat.el (eat--line-mode): Move all logic to 'eat-line-mode',
'eat--line-mode-exit' and 'eat--line-mode-exit-auto'.
* eat.el (eat-line-send): Make non-interactive. Reset input
history cycling variables.
* eat.el (eat-line-send-input): New argument NO-NEWLINE.
* eat.el (eat-mode): Don't disable undo information recording.
* eat.el (eat--process-output-queue): Disable undo information
recording while process output.
* eat.texi (Line Mode): New section in chapter 'Input Modes'.
* eat.texi (Line Mode Integration): New section in chapter
'Shell Integration'.
* eat.texi (Native Shell Prompt Editing): Remove section.
* README.org (Usage): Avoid the term "keybinding mode", use
"input mode" instead as the manual uses it. Document line
mode.
* README.org (NonGNU ELPA): Emacs 28 has NonGNU ELPA enabled by
default, so remove unnecessary instructions.
