docs: fewer claims, the right dependencies

README.md

@@ -46,8 +46,8 @@ that is not a jamo commit the syllable and go on to the application, so
 final they make (rt → ㄳ) and a vowel typed before its consonant is
 reordered under it (kr → 가), as in libhangul.
 
-Emoji and Hanja searches take over the keys until `Enter`, `Space`, or a
-digit picks a result or `Esc` cancels; they return to the previous mode
+Emoji and Hanja searches take over the keys until `Enter`, `Space`, or
+`1`-`9` picks a result or `Esc` cancels; they return to the previous mode
 after use, and switching language during a search commits the shown
 query. `Tab`/`Shift-Tab` wrap through the results, and a search with
 nothing typed yet shows ☺ or 漢 in the popup. The Emoji search matches the
@@ -88,8 +88,7 @@ display environment supports it.
 
 ## Build and test
 
-Initialize the bundled test library, then use the pinned Docker environment
-for a reproducible build:
+Initialize the bundled test library, then build in the Docker environment:
 
 ```sh
 git submodule update --init
@@ -118,8 +117,8 @@ tests. `make docker-check` rebuilds and runs all three tiers in the
 container, and `make docker-valgrind` runs the unit suite under Valgrind
 there; run `make docker-image` first after changing `Dockerfile`.
 
-Native Linux source builds require a C toolchain, Make, pkg-config, Python 3,
-and cmp/diff, plus development files for:
+Native Linux source builds require a C toolchain, Make, and pkg-config, plus
+development files for:
 
 - Plan 9 port (`9c`, `9l`, `libthread`, and `libbio`);
 - D-Bus development files;
@@ -127,6 +126,7 @@ and cmp/diff, plus development files for:
 - Pango, PangoCairo, Cairo, and Fontconfig;
 - GTK 3, plus libibus and Xlib for the live clients;
 - Xvfb for the X11 live tests;
+- Python 3 and `cmp` for `make check` and the map generators;
 - a working `C.UTF-8` locale and fonts covering Latin, CJK, and emoji.
 
 The package names used by the canonical Arch Linux image are listed in