cli: mention revsets doc on syntax error

Maybe we can show more specific hints on certain cases, but this should be good
as a fallback. The message is copied from the FilesetParseError hint.

cli/src/command_error.rs

@@ -811,6 +811,11 @@ fn revset_parse_error_hint(err: &RevsetParseError) -> Option<String> {
     // Only for the bottom error, which is usually the root cause
     let bottom_err = iter::successors(Some(err), |e| e.origin()).last().unwrap();
     match bottom_err.kind() {
+        RevsetParseErrorKind::SyntaxError => Some(
+            "See https://jj-vcs.github.io/jj/latest/revsets/ for revsets syntax, or for how to \
+             quote symbols."
+                .into(),
+        ),
         RevsetParseErrorKind::NotPrefixOperator {
             op: _,
             similar_op,

cli/tests/test_bookmark_command.rs

@@ -155,6 +155,7 @@ fn test_bookmark_bad_name() {
       = expected <identifier>, <string_literal>, or <raw_string_literal>
 
     For more information, try '--help'.
+    Hint: See https://jj-vcs.github.io/jj/latest/revsets/ for revsets syntax, or for how to quote symbols.
     [EOF]
     ");
 
@@ -181,6 +182,7 @@ fn test_bookmark_bad_name() {
       = expected <identifier>, <string_literal>, or <raw_string_literal>
 
     For more information, try '--help'.
+    Hint: See https://jj-vcs.github.io/jj/latest/revsets/ for revsets syntax, or for how to quote symbols.
     [EOF]
     ");
 
@@ -195,6 +197,7 @@ fn test_bookmark_bad_name() {
       = expected <identifier>, <string_literal>, or <raw_string_literal>
 
     For more information, try '--help'.
+    Hint: See https://jj-vcs.github.io/jj/latest/revsets/ for revsets syntax, or for how to quote symbols.
     [EOF]
     ");
 

cli/tests/test_revset_output.rs

@@ -42,6 +42,7 @@ fn test_syntax_error() {
       |    ^---
       |
       = expected `::`, `..`, `~`, or <primary>
+    Hint: See https://jj-vcs.github.io/jj/latest/revsets/ for revsets syntax, or for how to quote symbols.
     [EOF]
     ");
 
@@ -292,6 +293,7 @@ fn test_bad_function_call() {
       |                  ^---
       |
       = expected <strict_identifier> or <expression>
+    Hint: See https://jj-vcs.github.io/jj/latest/revsets/ for revsets syntax, or for how to quote symbols.
     [EOF]
     ");
 
@@ -304,6 +306,7 @@ fn test_bad_function_call() {
       |                         ^---
       |
       = expected <expression>
+    Hint: See https://jj-vcs.github.io/jj/latest/revsets/ for revsets syntax, or for how to quote symbols.
     [EOF]
     ");
 }
@@ -481,6 +484,7 @@ fn test_alias() {
       |           ^---
       |
       = expected `::`, `..`, `~`, or <primary>
+    Hint: See https://jj-vcs.github.io/jj/latest/revsets/ for revsets syntax, or for how to quote symbols.
     [EOF]
     ");