Fix links to logql docs (#29037)

public/app/plugins/datasource/loki/components/LokiCheatSheet.tsx

@@ -114,7 +114,7 @@ export default class LokiCheatSheet extends PureComponent<ExploreStartPageProps,
           {this.renderExpression('{app="cassandra"} |= "exact match"')}
           {this.renderExpression('{app="cassandra"} != "do not match"')}
           <div className="cheat-sheet-item__label">
-            <a href="https://github.com/grafana/loki/blob/master/docs/logql.md#filter-expression" target="logql">
+            <a href="https://grafana.com/docs/loki/latest/logql/#log-pipeline" target="logql">
               LogQL
             </a>{' '}
             supports exact and regular expression filters.

public/app/plugins/datasource/loki/datasource.test.ts

@@ -276,7 +276,7 @@ describe('LokiDatasource', () => {
         observable: ds.query(options),
         expect: err => {
           expect(err.data.message).toBe(
-            'Error: parse error at line 1, col 6: invalid char escape. Make sure that all special characters are escaped with \\. For more information on escaping of special characters visit LogQL documentation at https://github.com/grafana/loki/blob/master/docs/logql.md.'
+            'Error: parse error at line 1, col 6: invalid char escape. Make sure that all special characters are escaped with \\. For more information on escaping of special characters visit LogQL documentation at https://grafana.com/docs/loki/latest/logql/.'
           );
         },
         done,

public/app/plugins/datasource/loki/datasource.ts

@@ -520,7 +520,7 @@ export class LokiDatasource extends DataSourceApi<LokiQuery, LokiOptions> {
   processError(err: FetchError, target: LokiQuery) {
     let error = cloneDeep(err);
     if (err.data.message.includes('escape') && target.expr.includes('\\')) {
-      error.data.message = `Error: ${err.data.message}. Make sure that all special characters are escaped with \\. For more information on escaping of special characters visit LogQL documentation at https://github.com/grafana/loki/blob/master/docs/logql.md.`;
+      error.data.message = `Error: ${err.data.message}. Make sure that all special characters are escaped with \\. For more information on escaping of special characters visit LogQL documentation at https://grafana.com/docs/loki/latest/logql/.`;
     }
     return error;
   }