CHANGES: document --with-lua=PATH addition (trusteddomainproject#373)

Author: thegushi

CHANGES-2.11.0-alpha.md

@@ -102,7 +102,7 @@ A systematic audit of memory and resource leaks (issue #272) produced fixes acro
 
 - **`__P()` macro removed**: The K&R C compatibility shim was present in 400+ function prototypes across 36 files. musl libc (Alpine Linux and other minimal distros) does not define `__P()`, causing build failures there. Removed all uses; purely mechanical transformation to standard C prototypes. (#337, issue #140)
 - **`res_ninit()` configure detection**: On non-glibc platforms (FreeBSD, etc.), `resolv.h` requires prerequisite headers; the configure check was including only `resolv.h`, causing `res_ninit` to go undetected. Fixed by moving `AC_HEADER_RESOLV` before the check and adding the prerequisite headers to the test program. (#362, #297, issue #203)
-- **Lua detection rewrite**: Overhauled `configure.ac` Lua detection to use pkg-config where available, with manual fallback. Supports Lua 5.1-5.5, respects `LUA_CFLAGS`/`LUA_LIBS` environment variables, drops the stale `lua5.1` pkg-config name. **Note:** the configure flag was renamed from `--with-lua` to `--enable-lua` for autoconf compliance; update any build scripts accordingly. (#264, #266, #327, issues #111)
+- **Lua detection rewrite**: Overhauled `configure.ac` Lua detection to use pkg-config where available, with manual fallback. Supports Lua 5.1-5.5, respects `LUA_CFLAGS`/`LUA_LIBS` environment variables, drops the stale `lua5.1` pkg-config name. **Note:** the configure flag was renamed from `--with-lua` to `--enable-lua` for autoconf compliance; update any build scripts accordingly. `--with-lua=PATH` is also accepted as a prefix for non-standard installs (e.g. BSD systems with versioned header layouts) and implies `--enable-lua`. (#264, #266, #327, #373, issues #111)
 - **Lua 5.5 compatibility**: C API changes in Lua 5.5 (`lua_newstate` seed, `lua_pop` placement, writer function signature). (#267, #268, #328, issue #265)
 - **OpenSSL 3 EVP API**: Replaced deprecated `SHA1_Init/Update/Final` and `SHA256_Init/Update/Final` with the unified `EVP_MD_CTX` API. Drops `#ifdef HAVE_SHA256` guards. Compatible with OpenSSL 1.1.1 and 3.x. (#351, closes #162)
 - **OpenSSL version check**: Version comparison now ignores patch letter and status suffix, fixing false negatives on patch releases like `1.1.1n`. (#307, issue #178)