Issue #2898947 by rajandro, jungle, ankit.singh, AkashkumarOSL, Lal_, shimpy, Saurabh_sgh, markdorison, gnikolovski, jordanwood, librarylasso, Swapnil_Kotwal, mrinalini9, chiranjeeb2410, codersukanta, daffie, xjm, alexpott, mmjvb, mparker17, MaskyS, larowlan, quietone: Change "writeable" to "writable" in documentation

Issue #2749901 by MaskyS, kleog, priya.chat, harsha012, rakesh.gectcr, shobhit_juyal, snehi, SenthilMohith, neerajpandey, gawaksh, thompsizzle, ecrown, mohit1604, andrewmacpherson, surbz, rahulrasgon, riddhi.addweb: Add README.txt to Bartik theme

Issue #1507896 by b0unty, tuutti, Jeff Burnz, LewisNyman, tameeshb, realityloop, cbanman, umarzaffer, manumilou, mgifford, mducharme, oakulm, lauriii, alexpott, joelpittet, MaskyS, markcarver, xjm: Allow theme developers to add the default logo filename to the theme's .info.yml