Fix typos

I've added this typo to the `Naming/InclusiveLanguage` configuration
because I see it occasionally.

.rubocop.yml

@@ -105,6 +105,9 @@ Naming/InclusiveLanguage:
   Enabled: true
   CheckStrings: true
   FlaggedTerms:
+    ' a offense':
+      Suggestions:
+        - an offense
     auto-correct:
       Suggestions:
         - autocorrect

lib/rubocop/rspec/expect_offense.rb

@@ -6,7 +6,7 @@ module RSpec
     #
     # This mixin makes it easier to specify strict offense expectations
     # in a declarative and visual fashion. Just type out the code that
-    # should generate a offense, annotate code by writing '^'s
+    # should generate an offense, annotate code by writing '^'s
     # underneath each character that should be highlighted, and follow
     # the carets with a string (separated by a space) that is the
     # message of the offense. You can include multiple offenses in

spec/rubocop/cop/style/class_and_module_children_spec.rb

@@ -190,7 +190,7 @@ class BazClass < FooClass::BarClass
   context 'compact style' do
     let(:cop_config) { { 'EnforcedStyle' => 'compact' } }
 
-    it 'registers a offense for classes with nested children' do
+    it 'registers an offense for classes with nested children' do
       expect_offense(<<~RUBY)
         class FooClass
               ^^^^^^^^ Use compact module/class definition instead of nested style.
@@ -205,7 +205,7 @@ class FooClass::BarClass
       RUBY
     end
 
-    it 'registers a offense for modules with nested children' do
+    it 'registers an offense for modules with nested children' do
       expect_offense(<<~RUBY)
         module FooModule
                ^^^^^^^^^ Use compact module/class definition instead of nested style.
@@ -367,7 +367,7 @@ class BazModule
       RUBY
     end
 
-    it 'registers a offense for classes with nested one-liner children' do
+    it 'registers an offense for classes with nested one-liner children' do
       expect_offense(<<~RUBY)
         class FooClass
               ^^^^^^^^ Use compact module/class definition instead of nested style.

spec/rubocop/formatter/fuubar_style_formatter_spec.rb

@@ -100,7 +100,7 @@ def offense(severity, status = :uncorrected)
       end
     end
 
-    context 'when a offense is detected in a file and autocorrected' do
+    context 'when an offense is detected in a file and autocorrected' do
       before { formatter.file_finished(files[0], [offense(:convention, :corrected)]) }
 
       it 'is green' do

spec/rubocop/formatter/pacman_formatter_spec.rb

@@ -17,7 +17,7 @@
       end
     end
 
-    context 'when a offense is detected in a file' do
+    context 'when an offense is detected in a file' do
       let(:location) { FakeLocation.new(line: 1, column: 5) }
       let(:expected_character) { Rainbow(described_class::GHOST).red }
       let(:offenses) { [RuboCop::Cop::Offense.new(:error, location, 'message', 'CopA')] }

spec/rubocop/formatter/quiet_formatter_spec.rb

@@ -90,7 +90,7 @@
       end
     end
 
-    context 'when a offense detected' do
+    context 'when an offense detected' do
       it 'handles pluralization correctly' do
         formatter.report_summary(1, 1, 0, 0)
         expect(output.string).to eq(<<~OUTPUT)
@@ -100,7 +100,7 @@
       end
     end
 
-    context 'when a offense detected and a offense correctable' do
+    context 'when an offense detected and an offense correctable' do
       it 'handles pluralization correctly' do
         formatter.report_summary(1, 1, 0, 1)
         expect(output.string).to eq(<<~OUTPUT)

spec/rubocop/formatter/simple_text_formatter_spec.rb

@@ -113,7 +113,7 @@
       end
     end
 
-    context 'when a offense detected' do
+    context 'when an offense detected' do
       it 'handles pluralization correctly' do
         formatter.report_summary(1, 1, 0, 0)
         expect(output.string).to eq(<<~OUTPUT)
@@ -123,7 +123,7 @@
       end
     end
 
-    context 'when a offense detected and a offense autocorrectable' do
+    context 'when an offense detected and an offense autocorrectable' do
       it 'handles pluralization correctly' do
         formatter.report_summary(1, 1, 0, 1)
         expect(output.string).to eq(<<~OUTPUT)