feat: rename similar -> likewise

src/snapshots/likewise__udiff__unified_diff.snap

@@ -22,4 +22,3 @@ expression: "&diff.unified_diff().header(\"a.txt\", \"b.txt\").to_string()"
  P
  Q
  R
-

src/snapshots/likewise__udiff__unified_diff_newline_hint-2.snap

@@ -1,10 +1,9 @@
 ---
 source: src/udiff.rs
-expression: "&diff.unified_diff().missing_newline_hint(false).header(\"a.txt\",\n                                                        \"b.txt\").to_string()"
+expression: "&diff.unified_diff().missing_newline_hint(false).header(\"a.txt\",\n\"b.txt\").to_string()"
 ---
 --- a.txt
 +++ b.txt
 @@ -1 +1 @@
 -a
 +b
-

src/snapshots/likewise__udiff__unified_diff_newline_hint.snap

@@ -8,4 +8,3 @@ expression: "&diff.unified_diff().header(\"a.txt\", \"b.txt\").to_string()"
 -a
 +b
 \ No newline at end of file
-