Docs: remove em-dashes to match plx doc style

The existing docs use no em-dashes; the follow-up edits introduced four.
Replace with a semicolon / parentheses per the house style.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: plx

CHANGELOG.md

@@ -13,7 +13,7 @@ version in `plx.control` (currently `1.0`).
   dialect-neutral engine (declared in the new `src/plx_engine.h`) plus per-dialect
   front ends in `src/plx_dialect_*.c` and the shared `src/plx_parse_brace.c`;
   the hardcoded `block_style` dispatch is replaced by a per-dialect `parse_body`
-  function pointer. No functional change — generated plpgsql is byte-identical
+  function pointer. No functional change; generated plpgsql is byte-identical
   and all regression tests pass. Adding a dialect no longer touches shared code.
 - Follow-up to the above: relocated the dialect-neutral `plx_diag_prefix()`
   helper out of `src/plx_dialect_ruby.c` and back into the engine

doc/ARCHITECTURE.md

@@ -100,7 +100,7 @@ supplies. The surface describes what varies between languages:
 The transpiler is split into a dialect-neutral **engine** and per-dialect
 **front ends**, selected through the `parse_body` function pointer on the
 surface (a vtable method). `plx_transpile()` just calls
-`cx->surf->parse_body(cx)` and then runs one assemble tail — there is no
+`cx->surf->parse_body(cx)` and then runs one assemble tail; there is no
 per-dialect branching in the driver.
 
 - The **engine** lives in `plx_transpile.c` and is declared to the front ends
@@ -144,8 +144,8 @@ src/plx_dialect_tsql.c        the plxtsql surface + T-SQL front end
 Everything links into a single `plx.so`. A dialect is a `PlxSurface` (including
 its `parse_body` front end) plus small trampolines (validator, inline handler,
 and the shared call-handler binding), registered in `_PG_init`. Adding a dialect
-is a new `plx_dialect_X.c` — a surface with its `parse_body`, plus a few
-`CREATE LANGUAGE` lines — and does not touch the shared engine.
+is a new `plx_dialect_X.c` (a surface with its `parse_body`, plus a few
+`CREATE LANGUAGE` lines), and does not touch the shared engine.
 
 ## Trust