Add settings to enable or disable some rules on demand

[manuelarte]

This PR adds the possibility to enable or disable some "checks" in the funcorder linter.

Right now the linter checks the following:

• Struct's Constructors are placed after struct declaration.
• Struct's Constructors are placed before the struct's method declaration.
• Non-exported struct's methods are placed after exported ones.

But, I did not add 3 settings to enable/disable these checks, I only added two:

• constructor-check: Enable/Disable checks for bullet points 1 and 2.
• struct-method-check: Enable/Disable checks for bullet point 3.

Close #17

What do you guys think?

Work Pending:

• After this PR is merged, release v0.2.0
• Update Add funcorder linter golangci/golangci-lint#5630 with the new settings.

[alexandear]

I propose adding documentation to README.md for these options.

[manuelarte]

I propose adding documentation to README.md for these options.

I updated it with the following:

> funcorder [--constructor-check true|false] [--struct-methods-check true|false] ./...

Parameters:
* constructor-check: `true|false` (default `true`) enable|disable check constructor is placed after struct declaration and before struct's methods.
* struct-methods-check: `true|false` (default `true`) enable|disable check exported struct's methods are declared before non-exported.

[ldez]

FYI, I'm working on a refactor, I will open a PR after the merge of this one.

[manuelarte]

FYI, I'm working on a refactor, I will open a PR after the merge of this one.

amazing, looking forward to check it. If you approve this one we can merge it, I think all the points were resolved.

[ldez]

LGTM (but some elements will be refactored)

[manuelarte]

LGTM (but some elements will be refactored)

merged. I will wait for the refactor to release v0.2.0