Revert "Update contributing_to_ruby_on_rails.md"

This reverts commit 41ba51f4850a8cd2fe69789011ac33366366d32f.

[ci skip]
couple of tweaks to the release notes [ci skip]
Merge branch 'master' of github.com:lifo/docrails
Remove <tt> tag in 4_1_release notes. [ci skip].
Merge pull request #13408 from JuanitoFatas/remove-tt

Remove <tt> tag in 4_1_release notes. [ci skip].
revises the release notes about message verifiers [ci skip]

Example code does not run yet with beta1.
Revert "revises the release notes about message verifiers [ci skip]"

This reverts commit 293a1a68992ba3e3e80f9f0f685e866ff79bf11a.
revises the release notes about message verifiers (second take) [ci skip]
Change the message verifier argument to verifier_name
Make possible to use symbol as the verifier name
Make sure multiline string is not accepted by the regexp
Fix indent in PG array tests

[ci skip]
fix default select when from is used
Make `rails runner` command options more obvious


We're surrounding the options in angle brackets `<>` as is convention in `curl`:

```
$ curl --help
Usage: curl [options...] <url>
```

And then in square brackets `[]` with bars `|` as in `tar`:

```
$ tar --help
...
Create: tar -c [options] [<file> | <dir> | @<archive> | -C <dir> ]
```

To further clarify that the command can be used with both, we now show examples:

```
Examples:
    rails runner 'puts Rails.env'
        This runs the code `puts Rails.env` after loading the app

    rails runner path/to/filename.rb
        This runs the Ruby file located at `path/to/filename.rb` after loading the app
```

This format was taken from the `find` man pages:

```
EXAMPLES
     The following examples are shown as given to the shell:

     find / \! -name "*.c" -print
             Print out a list of all the files whose names do not end in .c.

     find / -newer ttt -user wnj -print
             Print out a list of all the files owned by user ``wnj'' that are newer than the file ttt.
```

The the text at the bottom is also shifted to improve readability.
Merge pull request #13344 from ccutrer/fix-from-default-select

fix default select when from is used
quoting: Check if id is a valid method before using it

Need to check if valud also respond_to :id before calling it, otherwise
things could explode.
Improve CHANGELOG entry [ci skip]
[ci skip] Describe precision + scale in migrations

Telling somebody that "precision sets the precision" is not very helpful.
Newbies want to know what precision is *for*, likewise with scale.

So I've added a very brief description for each.
Merge pull request #13411 from schneems/schneems/runner-command-dash-c

Make `rails runner` command options more obvious
Merge pull request #13412 from arthurnn/quote_id_not_id

quoting: Check if id is a valid method before using it