Add W3C Solid CG Charter (#323)

* Add W3C Solid CG Charter

* Apply suggestions from code review

* Apply suggestions from code review

* Minor

* Apply suggestions from code review

* Update solid-cg-charter.md

* Move Design Principles under Coordination and to follow Recs

* Add Amendments to this Charter section

* Add created, modified, version

* Add Solid QA towards improving Solid ecosystem and building confidence

* Apply suggestions from code review

Co-authored-by: Pierre-Antoine Champin <[email protected]>

* Replace 'drafts of specifications' with 'work items'

As per understanding in review thread: https://github.com/solid/process/pull/323/files/b8f5be17ad4e9f3a82e4ba1992216db7efd99b8a#r1263936639

* Refer to W3C Incubation and paraphrase CG focus/aim

In reply to: #323 (comment)

* Apply suggestions from code review

Co-authored-by: Ted Thibodeau Jr <[email protected]>

* Reference Work Items in Contributing Guide

As per https://github.com/solid/specification/blob/main/meetings/2023-07-19.md#add-work-items-section .

* Remove redundant line: on up to three chairs at any given time

* Add Vocabularies to Scope

Follows 2023-07-26 agreement: https://github.com/solid/specification/blob/main/meetings/2023-07-26.md#ui-layer-metadata

* Add examples to Federation in Scope

Co-authored-by: Wouter Termont <[email protected]>

* Remove access request/grants - captured by Authn/z in Scope

Co-authored-by: Wouter Termont <[email protected]>

* Add clarifications on participants/nominees wrt elections

* Clarify Scope items

Co-authored-by: Wouter Termont <[email protected]>

* Update Modified

* Add effective date

* Clarify W3C and MIT license use

As per resolution in [2023-08-09 Solid CG meeting](https://github.com/solid/specification/blob/main/meetings/2023-08-09.md#mit-license-andor-w3c-cla-and-fsa)

Co-authored-by: Wouter Termont <[email protected]>

* Correct spelling

Co-authored-by: Wouter Termont <[email protected]>

* Remove clause on deviations

Co-authored-by: Wouter Termont <[email protected]>

* Update License section

As per agreement in https://github.com/solid/specification/blob/main/meetings/2023-09-06.md#solid-cg-charter

Co-authored-by: Wouter Termont <[email protected]>

* Update modified

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Co-authored-by: Pierre-Antoine Champin <[email protected]>
Co-authored-by: Ted Thibodeau Jr <[email protected]>
Co-authored-by: Wouter Termont <[email protected]>