Update CHANGELOG

Author: josevalim

CHANGELOG.md

@@ -1,18 +1,97 @@
 # Changelog for Elixir v1.16
 
+## Code snippets in diagnostics
+
+Elixir v1.15 introduced a new compiler diagnostic format and the ability to print multiple error diagnostics per compilation (in addition to multiple warnings).
+
+With Elixir v1.16, we also include code snippets in exceptions and diagnostics raised by the compiler. For example, a syntax error now includes a pointer to where the error happened:
+
+```
+** (SyntaxError) invalid syntax found on nofile:1:17:
+    error: syntax error before: '*'
+    │
+  1 │ [1, 2, 3, 4, 5, *]
+    │                 ^
+    │
+    └─ lib/my_app.ex:1:17
+```
+
+For mismatched delimiters, it now shows both delimiters:
+
+```
+** (MismatchedDelimiterError) mismatched delimiter found on nofile:1:18:
+    error: unexpected token: )
+    │
+  1 │ [1, 2, 3, 4, 5, 6)
+    │ │                └ mismatched closing delimiter (expected "]")
+    │ └ unclosed delimiter
+    │
+    └─ lib/my_app.ex:1:18
+```
+
+Errors and warnings diagnostics also include code snippets. When possible, we will show precise spans, such as on undefined variables:
+
+```
+  error: undefined variable "unknown_var"
+  │
+5 │     a - unknown_var
+  │         ^^^^^^^^^^^
+  │
+  └─ lib/sample.ex:5:9: Sample.foo/1
+```
+
+Otherwise the whole line is underlined:
+
+```
+error: function names should start with lowercase characters or underscore, invalid name CamelCase
+  │
+3 │   def CamelCase do
+  │   ^^^^^^^^^^^^^^^^
+  │
+  └─ lib/sample.ex:3
+```
+
+## Revamped documentation
+
+TODO: Guides, diagrams, anti-patterns, cheatsheets.
+
 ## v1.16.0-dev
 
 ### 1. Enhancements
 
+#### EEx
+
+  * [EEx] Include relative file information in diagnostics
+
+#### Elixir
+
+  * [Code] Automatically include columns in parsing options
+  * [Code] Introduce `MismatchedDelimiterError` for handling mismatched delimiter exceptions
+  * [Code.Fragment] Handle anonymous calls in fragments
+  * [Kernel] Suggest module names based on suffix and casing errors when the module does not exist in `UndefinedFunctionError`
+  * [Kernel.ParallelCompiler] Introduce `Kernel.ParallelCompiler.pmap/2` to compile multiple additional entries in parallel
+  * [Macro] Add `Macro.compile_apply/4`
+  * [String] Update to Unicode 15.1.0
+
 ### 2. Bug fixes
 
 #### Elixir
 
   * [IO] Raise when using `IO.binwrite/2` on terminated device (mirroring `IO.write/2`)
+  * [Kernel] Do not expand aliases recursively (the alias stored in Macro.Env is already expanded)
+  * [Kernel] Ensure `dbg` module is a compile-time dependency
+  * [Kernel] Warn when a private function or macro uses `unquote/1` and the function/macro itself is unused
   * [Path] Ensure `Path.relative_to/2` returns a relative path when the given argument does not share a common prefix with `cwd`
 
+#### ExUnit
+
+  * [ExUnit] Raise on incorrectly dedented doctests
+
 ### 3. Soft deprecations (no warnings emitted)
 
+#### Elixir
+
+  * [Kernel.ParallelCompiler] Deprecate `Kernel.ParallelCompiler.async/1` in favor of `Kernel.ParallelCompiler.pmap/2`
   * [Path] Deprecate `Path.safe_relative_to/2` in favor of `Path.safe_relative/2`
 
 ### 4. Hard deprecations