docs(3p/nix): Clean up descriptions in Meson

1. Fix that for libsodium

  2. Consistently capitalize

(cherry picked from commit 12ce28bdf21d1f261132bdefe3dac25b1aab7dcc)

third_party/nix/meson.build

@@ -44,7 +44,7 @@ config_h = configuration_data()
 
 config_h.set(
     'HAVE_CXX17', 1,
-    description : 'define if the compiler supports basic C++17 syntax')
+    description : 'Define if the compiler supports basic C++17 syntax')
 
 package_name = meson.project_name()
 config_h.set_quoted(
@@ -383,7 +383,7 @@ boost_dep = declare_dependency(
     link_args :  get_option('boost_link_args'))
 
 if (boost_dep.found())
-    config_h.set('HAVE_BOOST', 1, description : 'define if the Boost library is available.')
+    config_h.set('HAVE_BOOST', 1, description : 'Define if the Boost library is available.')
 endif
 
 

third_party/nix/meson_options.txt

@@ -149,19 +149,19 @@ option(
     'with_gc',
     type : 'boolean',
     value : 'false',
-    description : 'build nix with Boehm garbage collector')
+    description : 'Build nix with Boehm garbage collector')
 
 option(
     'with_libsodium',
     type : 'feature',
     value : 'auto',
-    description : 'build nix with shared libs')
+    description : 'Build nix with libsodium')
 
 option(
     'with_s3',
     type : 'boolean',
     value : 'false',
-    description : 'build nix with s3')
+    description : 'Build nix with s3')
 
 option(
     'with_coreutils_bin',
@@ -182,7 +182,7 @@ option(
     'build_shared_libs',
     type : 'boolean',
     value : 'false',
-    description : 'build nix with shared libs')
+    description : 'Build nix with shared libs')
 
 option(
     'sandbox_shell',