pages*: fix names of operating systems (#12140)

pages/common/mongod.md

@@ -3,7 +3,7 @@
 > The MongoDB database server.
 > More information: <https://docs.mongodb.com/manual/reference/program/mongod>.
 
-- Specify the storage directory (default: `/data/db` on Linux and MacOS, `C:\data\db` on Windows):
+- Specify the storage directory (default: `/data/db` on Linux and macOS, `C:\data\db` on Windows):
 
 `mongod --dbpath {{path/to/directory}}`
 

pages/common/perl.md

@@ -7,7 +7,7 @@
 
 `perl -n -e 'print if m/{{regex1}}/ and m/{{regex2}}/i'`
 
-- Say [-E] first match group, using a regexp, ignoring space in regex [/x] :
+- Say [-E] first match group, using a regexp, ignoring space in regex [/x]:
 
 `perl -n -E 'say $1 if m/{{before}} (  {{group_regex}}  ) {{after}}/x'`
 
@@ -15,6 +15,6 @@
 
 `perl -i'.bak' -p -e 's/{{regex}}/{{replacement}}/g' {{path/to/files}}`
 
-- Use perl's inline documentation, some pages also available via man on linux:
+- Use perl's inline documentation, some pages also available via manual pages on Linux:
 
 `perldoc perlrun ; perldoc module ; perldoc -f splice; perldoc -q perlfaq1`

pages/common/venv.md

@@ -7,7 +7,7 @@
 
 ` python -m venv {{path/to/virtual_environment}}`
 
-- Activate the virtual environment (Linux and Mac OS):
+- Activate the virtual environment (Linux and macOS):
 
 `source {{path/to/virtual_environment}}/bin/activate`