add changelog for cabal-install-3.6.0.0

cabal-install/changelog

 -*-change-log-*-
+3.6.0.0 Emily Pillmore <emilypi@cohomolo.gy> August 2021
+	* See https://github.com/haskell/cabal/blob/master/release-notes/cabal-install-3.6.0.0.md
+
+3.4.0.0 Oleg Grenrus <oleg.grenrus@iki.fi> February 2021
+	* See https://github.com/haskell/cabal/blob/master/release-notes/cabal-install-3.4.0.0.md
 
 3.2.0.0 Herbert Valerio Riedel <hvr@gnu.org> April 2020
 	* `v2-build` (and other `v2-`prefixed commands) now accept the

release-notes/cabal-install-3.6.0.0.md

+### Backports
+
+- Backported to 3.4 [#6964](https://github.com/haskell/cabal/pull/6964) [#6968](https://github.com/haskell/cabal/pull/6968)
+- CI setup [#6959](https://github.com/haskell/cabal/pull/6959)
+
+  - Remove travis scripts
+
+### Significant Changes
+
+- Add post-checkout-command to source-package-repository [#6664](https://github.com/haskell/cabal/issues/6664) [#7047](https://github.com/haskell/cabal/pull/7047)
+- Assume list-bin target selectors are for executables [#7326](https://github.com/haskell/cabal/issues/7326) [#7335](https://github.com/haskell/cabal/pull/7335)
+- Add a --only-download flag [#7323](https://github.com/haskell/cabal/issues/7323) [#7347](https://github.com/haskell/cabal/pull/7347)
+- Add `hsc2hs-options`, for specifying additional options to pass to `hsc2hs` [#6295](https://github.com/haskell/cabal/pull/6295)
+- Make extra-packages work properly [#6972](https://github.com/haskell/cabal/pull/6972)
+- Bugfix - stop creating spurious dirs on `init` [#6772](https://github.com/haskell/cabal/issues/6772) [#7262](https://github.com/haskell/cabal/pull/7262)
+- Avoid resource exhaustion in `cabal init` [#5115](https://github.com/haskell/cabal/issues/5115) [#7283](https://github.com/haskell/cabal/pull/7283)
+
+  - Read file contents strictly to avoid resource exhaustion in `cabal init`.
+  - Ignore UTF-8 decoding errors.
+
+- Add language extensions for GHC 9.2 [#7312](https://github.com/haskell/cabal/issues/7312)
+- --dry-run and --only-download effect v2-configure, v2-freeze, v2-run, and v2-exec [#7379](https://github.com/haskell/cabal/issues/7379)
+- Fix instantiating an indefinite Backpack from Hackage with an inplace package [#6835](https://github.com/haskell/cabal/issues/6835) [#7413](https://github.com/haskell/cabal/pull/7413)
+
+  Previously, cabal-install would always attempt to put instantiations of indefinite packages from Hackage in
+  the global package store, even if they were instantiated with inplace packages.  This would not work
+  and GHC would complain about packages being missing from the package database.  We have fixed the
+  instantiation algorithm to correctly inplace packages in these situations, removing one of the last
+  blockers to widespread use of Backpack packages on Hackage.
+
+- removes the warnings for extraneous versions [#7286](https://github.com/haskell/cabal/issues/7286) [#7470](https://github.com/haskell/cabal/pull/7470)
+- Alert user and suggest command on spelling mistakes
+
+### Other improvements
+
+- Code organization [#6960](https://github.com/haskell/cabal/pull/6960) [#6963](https://github.com/haskell/cabal/pull/6963) [#6970](https://github.com/haskell/cabal/pull/6970) [#6974](https://github.com/haskell/cabal/pull/6974) [#6975](https://github.com/haskell/cabal/pull/6975)
+
+  - Move Cabal sources into Cabal/src
+  - Move cabal-install sources to cabal-install/src/
+  - Move doc/ to the top-level of the repository
+  - Add stylish-haskell config.
+
+- Documentation improvements [#6813](https://github.com/haskell/cabal/issues/6813) [#6971](https://github.com/haskell/cabal/pull/6971) [#7047](https://github.com/haskell/cabal/pull/7047)