Fix bin/dev bump-version to properly linkify changelog headers

[skip ci]

Author: ubolonton

CHANGELOG.md

@@ -5,7 +5,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 ## [Unreleased]
 
-## 0.17.0 - 2022-01-29
+## [0.17.0] - 2022-01-29
 - Added customization option `tsc-dyn-get-from`, which is a list of sources to get the dynamic module `tsc-dyn` from. Its default value is `(:github :compilation)`.
 - Made `tree-sitter-hl`'s region-fontification function fall back to the underlying non-tree-sitter function when called outside of `tree-sitter-hl-mode`. This fixes an issue where `jupyter-repl-mode`'s [input cells are not highlighted](https://github.com/nnicandro/emacs-jupyter/issues/363).
 - Updated `tsc-dyn-get` to download platform-specific binaries (mainly for Apple Silicon).
@@ -144,7 +144,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 ## [0.1.0] - 2020-01-27
 Initial release
 
-[Unreleased]: https://github.com/emacs-tree-sitter/elisp-tree-sitter/compare/0.16.1...HEAD
+[Unreleased]: https://github.com/emacs-tree-sitter/elisp-tree-sitter/compare/0.17.0...HEAD
+[0.17.0]: https://github.com/emacs-tree-sitter/elisp-tree-sitter/compare/0.16.1...0.17.0
 [0.16.1]: https://github.com/emacs-tree-sitter/elisp-tree-sitter/compare/0.16.0...0.16.1
 [0.16.0]: https://github.com/emacs-tree-sitter/elisp-tree-sitter/compare/0.15.2...0.16.0
 [0.15.2]: https://github.com/emacs-tree-sitter/elisp-tree-sitter/compare/0.15.1...0.15.2

bin/dev

@@ -91,9 +91,15 @@
       (-modify-regexp "Version: *\\(.*\\)" next)
       (-modify-regexp "Package-Requires:.*\(tsc *\"\\(.*\\)\"" next))
     (-with-file-edits CHANGELOG.md
-      (search-forward "Unreleased")
+      (search-forward "[Unreleased]")
       (end-of-line)
-      (insert (format "\n\n## %s - %s" next date)))    ))
+      (insert (format "\n\n## [%s] - %s" next date))
+      (search-forward "[Unreleased]")
+      (search-forward current)
+      (replace-match next)
+      (end-of-line)
+      (insert (format "\n[%s]: https://github.com/emacs-tree-sitter/elisp-tree-sitter/compare/%s...%s"
+                      next current next)))))
 
 (defun cmd:current-version ()
   "Print the current version."