gocritic enabled-checks and disabled-checks can be combined

The documentation currently indicates that enable-checks and
disabled-checks can't be combined for gocritic. That is however not
accurate: as per InferEnabledChecks in the gocritic wrapper,

* if enable-all is set, all available checks are added to the set of
  enabled checks
* otherwise, unless disable-all is set, the default checks are added
  to the set of enabled checks
* then the checks corresponding to each enabled tag are added
* then all enabled checks are added (with a warning if a check is
  enabled multiple times)
* then the checks corresponding to each disabled tag are removed
* finally, all disabled checks are removed (with a warning if a check
  wasn't enabled)

Using both enabled-checks and disabled-checks is useful when keeping
the default set of checks as reference.

This adjusts the documentation to match the implementation.

Signed-off-by: Stephen Kitt <skitt@redhat.com>

Author: skitt

.golangci.next.reference.yml

@@ -727,8 +727,8 @@ linters-settings:
     # Disable all checks.
     # Default: false
     disable-all: true
-    # Which checks should be enabled in addition to default checks; can't be combined with 'disabled-checks'.
-    # By default, list of stable checks is used (https://go-critic.com/overview#checks-overview):
+    # Which checks should be enabled in addition to default checks (or at all, if disable-all is true).
+    # The default checks are gocritic's stable checks (https://go-critic.com/overview#checks-overview):
     #   appendAssign, argOrder, assignOp, badCall, badCond, captLocal, caseOrder, codegenComment, commentFormatting,
     #   defaultCaseOrder, deprecatedComment, dupArg, dupBranchBody, dupCase, dupSubExpr, elseif, exitAfterDefer,
     #   flagDeref, flagName, ifElseChain, mapKey, newDeref, offBy1, regexpMust, singleCaseSwitch, sloppyLen,
@@ -1057,7 +1057,7 @@ linters-settings:
     # Enable all checks.
     # Default: false
     enable-all: true
-    # Which checks should be disabled; can't be combined with 'enabled-checks'.
+    # Which checks should be disabled.
     # Default: []
     disabled-checks:
       - appendAssign

.golangci.reference.yml

@@ -727,8 +727,8 @@ linters-settings:
     # Disable all checks.
     # Default: false
     disable-all: true
-    # Which checks should be enabled in addition to default checks; can't be combined with 'disabled-checks'.
-    # By default, list of stable checks is used (https://go-critic.com/overview#checks-overview):
+    # Which checks should be enabled in addition to default checks (or at all, if disable-all is true).
+    # The default checks are gocritic's stable checks (https://go-critic.com/overview#checks-overview):
     #   appendAssign, argOrder, assignOp, badCall, badCond, captLocal, caseOrder, codegenComment, commentFormatting,
     #   defaultCaseOrder, deprecatedComment, dupArg, dupBranchBody, dupCase, dupSubExpr, elseif, exitAfterDefer,
     #   flagDeref, flagName, ifElseChain, mapKey, newDeref, offBy1, regexpMust, singleCaseSwitch, sloppyLen,
@@ -1057,7 +1057,7 @@ linters-settings:
     # Enable all checks.
     # Default: false
     enable-all: true
-    # Which checks should be disabled; can't be combined with 'enabled-checks'.
+    # Which checks should be disabled.
     # Default: []
     disabled-checks:
       - appendAssign