docs: remove misleading either from the description of or label filters

docs/MetricsQL.md

@@ -70,7 +70,7 @@ The list of MetricsQL features on top of PromQL:
   It is equivalent to `rate(node_network_receive_bytes_total[$__interval])` when used in Grafana.
 * Numeric values can contain `_` delimiters for better readability. For example, `1_234_567_890` can be used in queries instead of `1234567890`.
 * [Series selectors](https://docs.victoriametrics.com/keyConcepts.html#filtering) accept multiple `or` filters. For example, `{env="prod",job="a" or env="dev",job="b"}`
-  selects series with either `{env="prod",job="a"}` or `{env="dev",job="b"}` labels.
+  selects series with `{env="prod",job="a"}` or `{env="dev",job="b"}` labels.
   See [these docs](https://docs.victoriametrics.com/keyConcepts.html#filtering-by-multiple-or-filters) for details.
 * Support for `group_left(*)` and `group_right(*)` for copying all the labels from time series on the `one` side
   of [many-to-one operations](https://prometheus.io/docs/prometheus/latest/querying/operators/#many-to-one-and-one-to-many-vector-matches).

docs/keyConcepts.md

@@ -834,7 +834,7 @@ The query above returns series for two metrics: `requests_error_total` and `requ
 
 [MetricsQL](https://docs.victoriametrics.com/MetricsQL.html) supports selecting time series, which match at least one of multiple "or" filters.
 Such filters must be delimited by `or` inside curly braces. For example, the following query selects time series with
-either `{job="app1",env="prod"}` or `{job="app2",env="dev"}` labels:
+`{job="app1",env="prod"}` or `{job="app2",env="dev"}` labels:
 
 ```metricsql
 {job="app1",env="prod" or job="app2",env="dev"}