<commit_before># mailer

Implemented providers:

- Fake (writes mail output to stdout)
- Gmail
- Mailgun

Example:
```go
m := NewFakeMailer()

err := m.Send(Email{
    To:      "<EMAIL>",
    From:    "<EMAIL>",
    Subject: "Something important",
    Body: Body{
        Text: "Hello you",
        HTML: "<strong>Hello you</strong>",
    },
})
if err != nil {
    panic(err)
}<commit_msg>improved example code<commit_after># mailer

Implemented providers:

- Fake (writes mail output to stdout)
- Gmail
- Mailgun

Example:
```go
m := mailer.NewFakeMailer()

err := m.Send(mailer.Email{
    To:      "<EMAIL>",
    From:    "<EMAIL>",
    Subject: "Something important",
    Body: mailer.Body{
        Text: "Hello you",
        HTML: "<strong>Hello you</strong>",
    },
})
if err != nil {
    panic(err)
}
{'fraction_non_alphanumeric': 0.1623296158612144, 'fraction_numerical': 0.0, 'mean_word_length': 2.811320754716981, 'pattern_counts': {'":': 0, '<': 11, '<?xml version=': 0, '>': 11, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
{'dir': 'git-commits-cleaned', 'id': '7612009', 'n_tokens_mistral': 286, 'n_tokens_neox': 285, 'n_words': 76}