docs: Add missing language identifier [skip ci]

docs/markdown/Dependencies.md

@@ -315,7 +315,8 @@ as getting it to work standalone is tricky.
 
 You can set the `main` keyword argument to `true` to use the `main()`
 function provided by GTest:
-```
+
+```meson
 gtest_dep = dependency('gtest', main : true, required : false)
 e = executable('testprog', 'test.cc', dependencies : gtest_dep)
 test('gtest test', e)

docs/markdown/Reference-manual.md

@@ -709,14 +709,16 @@ set). Hence, you *must not* manually add the interpreter while using
 this script as part of a list of commands.
 
 If you need to check for a program in a non-standard location, you can
-just pass an absolute path to `find_program`, e.g.  ``` setcap =
-find_program('setcap', '/usr/sbin/setcap', '/sbin/setcap', required :
-false) ```
+just pass an absolute path to `find_program`, e.g.
+
+```meson
+setcap = find_program('setcap', '/usr/sbin/setcap', '/sbin/setcap', required : false)
+```
 
 It is also possible to pass an array to `find_program` in case you
 need to construct the set of paths to search on the fly:
 
-```
+```meson
 setcap = find_program(['setcap', '/usr/sbin/setcap', '/sbin/setcap'], required : false)
 ```
 

docs/markdown/Release-notes-for-0.46.0.md

@@ -292,7 +292,7 @@ default value will be provided for all required fields of the pc file:
 
 Generating a .pc file is now as simple as:
 
-```
+```meson
 pkgconfig.generate(mylib)
 ```