Issue #3426309 by Wim Leers, smustgrave: Add config validation for weights (blocks, filters, etc. all use weights)

Issue #3341682 by Wim Leers, phenaproxima, borisson_, catch, alexpott: New config schema data type: required_label

Issue #3377030 by Wim Leers, borisson_, smustgrave: Add validation constraint to `type: label`: disallow multiple lines

Issue #2920678 by phenaproxima, Wim Leers, dawehner, Gogowitsch, Sam152, dww, longwave, yogeshmpawar, alexpott, borisson_, tstoeckler, jibran, amateescu, larowlan, tedbow: Add config validation for the allowed characters of machine names

Issue #306662 by naveenvalecha, andypost, larowlan, tim-e, mr.baileys, pguillard, alexpott, hussainweb, frankcarey, Tor Arne Thune, deepakaryan1988, jibran, tstoeckler: Add redirect option to site-wide contact forms

Issue #2625696 by chx, benjy, alexpott, catch, mikeryan, andypost, phenaproxima: Make migrations themselves plugins instead of config entities

Revert "Issue #2625696 by chx, alexpott, benjy, mikeryan, andypost, phenaproxima: Make migrations themselves plugins instead of config entities"

This reverts commit 694994fe.

Issue #2625696 by chx, alexpott, benjy, mikeryan, andypost, phenaproxima: Make migrations themselves plugins instead of config entities

Issue #2459971 by Gábor Hojtsy: The langcode key on configuration files is not explicit in configuration schema

Issue #2349651 by larowlan, yannisc: Fixed Default contact form does not send email as email recipient is not set during the installation.

Issue #2342551 by larowlan: Implement ThirdPartySettingsInterface in contact module for contact form config entity.

Issue #2256679 by alexpott, tim.plunkett: Fixed Use config schema to determine which config entity properties to export regardless of whether they are public or protected.

Issue #950534 by mparker17, mgifford, Mixologic, jbloomfield, erinclerico, theMusician, wmostrey | zirvap: [policy] Consistently use email instead of e-mail in Drupal.

Issue #2233787 by alexpott, xjm | tim.plunkett: Move default configuration into extension/config/install to clarify its purpose.

Issue #2167623 by danilenko_dn, sidharthap, Nitesh Sethia, krishnan.n, aitiba, alexpott, ashwinikumar, Barrett, damiankloip, deepakaryan1988, foxtrotcharlie, ianthomas_uk, neetu morwani, nonsie, piyuesh23, Sharique, sivaji, sushantpaste, swentel, vijaycs85, YesCT: Add test for all default configuration to ensure schema exists and is correct.

Issue #1856556 by Berdir, andypost, das-peter: Convert user contact form into a contact category/bundle.

Issue #1964254 by vijaycs85, YesCT | Gábor Hojtsy: Fixed Configuration schemas missing langcode and uuid at places.

Issue #1947814 by vijaycs85, Gábor Hojtsy, tim.plunkett: Fixed New config entities often save as langcode: und incorrectly.

Issue #1942120 by sandipmkhairnar: Fixed Make Contact module active config save format match the default yml file.

Issue #1914366 by vijaycs85, Gábor Hojtsy, alexpott: Move all configuration schema files into a schema subdirectory.

Issue #1866610 by Jose Reyero, Gábor Hojtsy, effulgentsia, alexpott, aspilicious, YesCT, fago, sun, dawehner, heyrocker, yched, spearhead93: Introduce Kwalify-inspired schema format for configuration.

Issue #1588422 by andypost, sun, disasm, dawehner, vasi1186, alexpott, tim.plunkett, larowlan: Convert contact categories to configuration system.

Issue #1588422 by andypost, disasm, sun, dawehner, vasi1186, alexpott, tim.plunkett, larowlan, Gábor Hojtsy: Convert contact categories to configuration system.

Issue #1704530 by alexpott, aspilicious: [HEAD BROKEN] Convert contact module variables to configuration system.