Don't ignore stack lock file.

Author: alexandru-dinu

.gitignore

@@ -1,5 +1,4 @@
 *~
-*.lock
 dist
 dist-*
 cabal-dev
@@ -183,4 +182,4 @@ cython_debug/
 #  be found at https://github.com/github/gitignore/blob/main/Global/JetBrains.gitignore
 #  and can be added to the global gitignore or merged into this file.  For a more nuclear
 #  option (not recommended) you can uncomment the following to ignore the entire idea folder.
-#.idea/
+#.idea/

stack.yaml.lock

@@ -0,0 +1,13 @@
+# This file was autogenerated by Stack.
+# You should not edit this file by hand.
+# For more information, please see the documentation at:
+#   https://docs.haskellstack.org/en/stable/lock_files
+
+packages: []
+snapshots:
+- completed:
+    sha256: 3770dfd79f5aed67acdcc65c4e7730adddffe6dba79ea723cfb0918356fc0f94
+    size: 648660
+    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/20/4.yaml
+  original:
+    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/20/4.yaml