sphinx-copybutton-exclude-issue

sphinx-copybutton versions: v0.5.1, v0.5.1 add ‘.go’ to copybutton_exclude, v0.5.0

v0.5.1 copies output, v0.5.0 doesn’t

```console
$ echo "11"
11
$ echo "22"
22
```

$ echo "11"
11
$ echo "22"
22

Adding .go to exclude

Following DOCS: Improve docs related to text exclusion #187, adding .go to exclude will break multi-line snippets in v0.5.1.

```console
$ cat << EOT > notes.txt
   This is an example sentence.
       Put some indentation on this line.

  EOT
```

$ cat << EOT > notes.txt
   This is an example sentence.
       Put some indentation on this line.

  EOT

These lines will have .go class and excluded in v0.5.1

   This is an example sentence.
       Put some indentation on this line.

  EOT

My conf.py

copybutton_prompt_text = r">>> |\.\.\. |\$ |In \[\d*\]: | {2,5}\.\.\.: | {5,8}: "
copybutton_prompt_is_regexp = True
copybutton_line_continuation_character = "\\"
copybutton_here_doc_delimiter = "EOT"
copybutton_selector = "div:not(.no-copybutton) > div.highlight > pre"