Fix instructions for Debian/Ubuntu to have shims ahead of ~/.local/bin (#1977)

Debian/Ubuntu's stock `~/.bashrc` prepends `~/.local/bin` to `PATH` towards its end if it exists.
Executables for per-user modules for system Python are installed into `~/.local/bin` --
so need to prepend `shims` to `PATH` later that that.

Co-authored-by: Ivan Pozdeev <vano@mail.mipt.ru>

README.md

@@ -240,6 +240,10 @@ easy to fork and contribute any changes back upstream.
             ~~~bash
             export PYENV_ROOT="$HOME/.pyenv"
             export PATH="$PYENV_ROOT/bin:$PATH"
+            ~~~
+            
+            And put this line at the _bottom_ of `~/.profile`:
+            ~~~bash
             eval "$(pyenv init --path)"
             ~~~