Update the user facing docs

docs/user/metrics/labeled_counters.md

@@ -43,7 +43,7 @@ assertEquals(3, Stability.crashCount["native_code_crash"].testGetValue())
 
 ## Limits
 
-* Each label must be in `snake_case` (and also may contain `.`).
+* Labels support alphanumeric characters; they additionally allow for docs, underscores and/or hyphens.
 
 * Each label must have a maximum of 60 characters.
 

docs/user/metrics/labeled_strings.md

@@ -39,7 +39,8 @@ assertTrue(Login.errorsByStage["server_auth"].testHasValue())
 
 ## Limits
 
-* Each label must be in `snake_case` (and also may contain `.`).
+
+* Labels support alphanumeric characters; they additionally allow for docs, underscores and/or hyphens.
 
 * Each label must have a maximum of 60 characters.
 

docs/user/metrics/labeled_timespans.md

@@ -60,7 +60,8 @@ assertTrue(Auth.timesPerStage["auth_with_server"].testGetValue() > 0)Now you can
 
 ## Limits
 
-* Each label must be in `snake_case` (and also may contain `.`).
+
+* Labels support alphanumeric characters; they additionally allow for docs, underscores and/or hyphens.
 
 * Each label must have a maximum of 60 characters.