Unify spacing and wording in the Japanese docs pages

Drop the spaces between Japanese text and inline code or alphanumerics
in the tour and the few other pages that still had them, and reword
sentences that read awkwardly. The client compression page now lists
Zstd alongside zlib and Brotli.

docs-src/pages/en/cookbook/c15-compression.md

@@ -4,7 +4,7 @@ order: 15
 status: "draft"
 ---
 
-cpp-httplib supports compression when sending and decompression when receiving. You just need to build it with zlib or Brotli enabled.
+cpp-httplib supports compression when sending and decompression when receiving. You just need to build it with zlib, Brotli, or Zstd enabled.
 
 ## Build-time setup
 
@@ -13,10 +13,11 @@ To use compression, define these macros before including `httplib.h`:
 ```cpp
 #define CPPHTTPLIB_ZLIB_SUPPORT    // gzip / deflate
 #define CPPHTTPLIB_BROTLI_SUPPORT  // brotli
+#define CPPHTTPLIB_ZSTD_SUPPORT    // zstd
 #include <httplib.h>
 ```
 
-You'll also need to link against `zlib` or `brotli`.
+You'll also need to link against `zlib`, `brotli`, or `zstd`, whichever you enabled.
 
 ## Compress the request body