Update links to the documentation in validate.proto (#370)

Author: timostamm

proto/protovalidate/buf/validate/validate.proto

@@ -76,7 +76,7 @@ extend google.protobuf.FieldOptions {
 // `Rule` represents a validation rule written in the Common Expression
 // Language (CEL) syntax. Each Rule includes a unique identifier, an
 // optional error message, and the CEL expression to evaluate. For more
-// information on CEL, [see our documentation](https://github.com/bufbuild/protovalidate/blob/main/docs/cel.md).
+// information, [see our documentation](https://buf.build/docs/protovalidate/schemas/custom-rules/).
 //
 // ```proto
 // message Foo {
@@ -121,8 +121,8 @@ message MessageRules {
   optional bool disabled = 1;
 
   // `cel` is a repeated field of type Rule. Each Rule specifies a validation rule to be applied to this message.
-  // These rules are written in Common Expression Language (CEL) syntax. For more information on
-  // CEL, [see our documentation](https://github.com/bufbuild/protovalidate/blob/main/docs/cel.md).
+  // These rules are written in Common Expression Language (CEL) syntax. For more information,
+  // [see our documentation](https://buf.build/docs/protovalidate/schemas/custom-rules/).
   //
   //
   // ```proto
@@ -166,8 +166,8 @@ message OneofRules {
 // the field, the correct set should be used to ensure proper validations.
 message FieldRules {
   // `cel` is a repeated field used to represent a textual expression
-  // in the Common Expression Language (CEL) syntax. For more information on
-  // CEL, [see our documentation](https://github.com/bufbuild/protovalidate/blob/main/docs/cel.md).
+  // in the Common Expression Language (CEL) syntax. For more information,
+  // [see our documentation](https://buf.build/docs/protovalidate/schemas/custom-rules/).
   //
   // ```proto
   // message MyMessage {
@@ -251,8 +251,8 @@ message FieldRules {
 // multiple fields.
 message PredefinedRules {
   // `cel` is a repeated field used to represent a textual expression
-  // in the Common Expression Language (CEL) syntax. For more information on
-  // CEL, [see our documentation](https://github.com/bufbuild/protovalidate/blob/main/docs/cel.md).
+  // in the Common Expression Language (CEL) syntax. For more information,
+  // [see our documentation](https://buf.build/docs/protovalidate/schemas/predefined-rules/).
   //
   // ```proto
   // message MyMessage {