chore: Add .git-blame-ignore-revs (a2aproject#28)

Author: holtskinner

.git-blame-ignore-revs

@@ -0,0 +1,21 @@
+# Template taken from https://github.com/v8/v8/blob/master/.git-blame-ignore-revs.
+#
+# This file contains a list of git hashes of revisions to be ignored by git blame. These
+# revisions are considered "unimportant" in that they are unlikely to be what you are
+# interested in when blaming. Most of these will probably be commits related to linting
+# and code formatting.
+#
+# Instructions:
+# - Only large (generally automated) reformatting or renaming CLs should be
+#   added to this list. Do not put things here just because you feel they are
+#   trivial or unimportant. If in doubt, do not put it on this list.
+# - Precede each revision with a comment containing the PR title and number.
+#   For bulk work over many commits, place all commits in a block with a single
+#   comment at the top describing the work done in those commits.
+# - Only put full 40-character hashes on this list (not short hashes or any
+#   other revision reference).
+# - Append to the bottom of the file (revisions should be in chronological order
+#   from oldest to newest).
+# - Because you must use a hash, you need to append to this list in a follow-up
+#   PR to the actual reformatting PR that you are trying to ignore.
+193693836e1ed8cd361e139668323d2e267a9eaa