nvd.1: Escape characters that are special according to groff_char(7).

src/nvd.1

@@ -202,9 +202,9 @@ symlink or a symlink to such a path. Valid examples include:
 .br
 	- /nix/var/nix/profiles/default
 .br
-	- ~/.nix-profile
+	- \(ti/.nix-profile
 .br
-	- ~/.local/state/nix/profiles/profile
+	- \(ti/.local/state/nix/profiles/profile
 .br
 	- /nix/var/nix/profiles/per-user/myself/profile
 .br
@@ -271,7 +271,7 @@ following.
 .RS
 .EX
 [U.]  #1  linux                   5.4.99 -> 5.4.100
- ^^   ^   ^                       ^
+ \(ha\(ha   \(ha   \(ha                       \(ha
  ||   |   package name            package versions
  ||   count of packages within the section
  |package selection state