Add an uncrustify configuration (code prettifier)

The `uncrustify` tool is an extremely configurable code prettifier that
is actively maintained and has extensive options for debugging
formatting issues. See https://uncrustify.sourceforge.net/ for more
details.

Let's add a configuration that can help contributors auto-format their
code to allow them to focus on the actual goal of their improvements.

This requires uncrustify 0.78.0 or newer.

Co-authored-by: Johannes Schindelin <[email protected]>
Signed-off-by: Johannes Schindelin <[email protected]>

contrib/uncrustify/uncrustify.cfg

@@ -0,0 +1,52 @@
+#
+# uncrustify config file for the Git project
+#
+# Run it in a git/git worktree like this:
+#
+#    uncrustify -c contrib/uncrustify/uncrustify.cfg \
+#        --replace --no-backup --if-changed <file>
+#
+# Or run it on all source files:
+#
+#    printf 'include Makefile\n\nsources:\n\t@echo $(COCCI_SOURCES)\n' |
+#    make -f - sources |
+#    xargs -r uncrustify -c contrib/uncrustify/uncrustify.cfg \
+#        --replace --no-backup --if-changed
+#
+# This configuration requires uncrustify 0.78.0 or newer.
+#
+
+align_keep_tabs                 = TRUE
+align_with_tabs                 = TRUE
+align_on_tabstop                = FALSE
+
+cmt_indent_multi                = FALSE
+
+align_right_cmt_span            = 3
+align_keep_extra_space          = TRUE
+indent_comment_align_thresh     = 16
+cmt_trailing_single_line_c_to_cpp = FALSE
+
+indent_with_tabs                = 2
+indent_comment                  = FALSE
+indent_align_string             = TRUE
+indent_align_assign             = FALSE
+
+pp_ignore_define_body           = TRUE
+
+sp_enum_colon                   = remove
+
+# Add or remove space before a trailing comment.
+sp_before_tr_cmt                = ignore   # ignore/add/remove/force/not_defined
+
+# Number of spaces before a trailing comment.
+sp_num_before_tr_cmt            = 1        # unsigned number
+
+sp_before_sparen                = force
+sp_func_call_paren              = remove
+sp_func_proto_paren             = remove
+sp_after_semi                   = remove
+
+# Bit field colons should not be enclosed in spaces
+sp_after_bit_colon              = remove
+sp_before_bit_colon             = remove