find: quotes outside tokens; generic extension (#1160)

The generic extension is to conform to our contribution guidelines:
https://github.com/tldr-pages/tldr/blob/master/CONTRIBUTING.md#token-syntax

pages/common/find.md

@@ -4,27 +4,27 @@
 
 - Find files by extension:
 
-`find {{root_path}} -name {{'*.py'}}`
+`find {{root_path}} -name '{{*.ext}}'`
 
 - Find files matching path pattern:
 
-`find {{root_path}} -path {{'**/lib/**/*.py'}}`
+`find {{root_path}} -path '{{**/lib/**/*.ext}}'`
 
 - Run a command for each file, use {} within the command to access the filename:
 
-`find {{root_path}} -name {{'*.py'}} -exec {{wc -l {} }}\;`
+`find {{root_path}} -name '{{*.ext}}' -exec {{wc -l {} }}\;`
 
 - Find files modified since a certain time:
 
-`find {{root_path}} -name {{'*.py'}} -mtime {{-1d}}`
+`find {{root_path}} -name '{{}}' -mtime {{-1d}}`
 
 - Find files using case insensitive name matching, of a certain size:
 
-`find {{root_path}} -size +500k -size -10MB -iname {{'*.TaR.gZ'}}`
+`find {{root_path}} -size +500k -size -10MB -iname '{{*.TaR.gZ}}'`
 
 - Delete files by name, older than a certain number of days:
 
-`find {{root_path}} -name {{'*.py'}} -mtime {{-180d}} -delete`
+`find {{root_path}} -name '{{*.ext}}' -mtime {{-180d}} -delete`
 
 - Find empty files or directories:
 
@@ -32,4 +32,4 @@
 
 - Find files matching more than one search criteria:
 
-`find {{root_path}} -name {{'*.py'}} -or -name {{'*.r'}}`
+`find {{root_path}} -name '{{*.py}}' -or -name '{{*.r}}'`