ChangeLog housekeeping.

Archive old `ChangeLog` file.

We no longer write ChangeLog entries manually; instead, the file will be
created from commit messages (which should be formatted in GNU's ChangeLog
style) by a call to

  gitlog-to-changelog --format='%B%n'

or something similar (this script is part of the 'gnulib' repository).
diff --git a/.gitattributes b/.gitattributes
deleted file mode 100644
index 31f962f..0000000
--- a/.gitattributes
+++ /dev/null
@@ -1 +0,0 @@
-ChangeLog       merge=merge-changelog
diff --git a/README.git b/README.git
index 2bed537..b4c0703 100644
--- a/README.git
+++ b/README.git
@@ -72,26 +72,6 @@
 submodule and copies some files into FreeType's source tree.
-If you want to contribute to FreeType it is recommended to install the
-`git-merge-changelog` program – we use a `ChangeLog` file, which often
-prevents   simple   merging   due  to   conflicts.    Most   GNU/Linux
-distributions  have a  package  for this  program;  otherwise you  can
-install it via the 'gnulib' git repository.  Detailed instructions can
-be found at the beginning of
-To make  it actually work, add  to file `.git/config` in  the FreeType
-git repository (or to your `$HOME/.gitconfig` file) the lines
-  [merge "merge-changelog"]
-     name = GNU-style ChangeLog merge driver
-     driver = /usr/local/bin/git-merge-changelog %O %A %B
 Copyright (C) 2005-2021 by
diff --git a/ChangeLog b/docs/oldlogs/ChangeLog.210
similarity index 100%
rename from ChangeLog
rename to docs/oldlogs/ChangeLog.210