docs(installation): add missing cautions for bash-preexec

This is also the descriptions in README.md (@atuinsh/atuin) removed by
[1] and not reflected in atuinsh/docs.

[1] atuinsh/atuin#2203

Author: akinomyoga

src/content/docs/guide/installation.mdx

@@ -150,6 +150,14 @@ After installing, remember to restart your shell.
                     bash-preexec currently has an issue where it will stop honoring `ignorespace`.
                     While Atuin will ignore commands prefixed with whitespace, they may still end up in your bash history.
                     Please check your configuration! All other shells do not have this issue.
+
+                    To use Atuin in `bash < 4` with bash-preexec, the option `enter_accept` needs
+                    to be turned on (which is so by default).
+
+                    bash-preexec cannot properly invoke the `preexec` hook for subshell commands
+                    `(...)`, function definitions `func() { ...; }`, empty for-in-statements `for
+                    i in; do ...; done`, etc., so those commands and duration may not be recorded
+                    in the Atuin's history correctly.
                 </Aside>
 
                 To use bash-preexec, download and initialize it