tools: Update tidy.sh and related configs

Author: taiki-e

.editorconfig

@@ -11,12 +11,14 @@ indent_style = space
 insert_final_newline = true
 trim_trailing_whitespace = true
 
-[*.{json,md,rb,sh,yml,yaml}]
+[*.{css,html,json,md,rb,sh,yml,yaml}]
 indent_size = 2
 
 [*.{js,yml,yaml}]
 quote_type = single
 
 [*.sh]
+# https://google.github.io/styleguide/shellguide.html#s5.3-pipelines
 binary_next_line = true
+# https://google.github.io/styleguide/shellguide.html#s5.5-case-statement
 switch_case_indent = true

.shellcheckrc

@@ -2,13 +2,34 @@
 # https://github.com/koalaman/shellcheck/blob/HEAD/shellcheck.1.md#rc-files
 
 # See also:
-# https://www.shellcheck.net/wiki/Optional
+# https://github.com/koalaman/shellcheck/wiki/Optional
 # https://google.github.io/styleguide/shellguide.html
 
-# https://www.shellcheck.net/wiki/SC2292
+# https://github.com/koalaman/shellcheck/wiki/SC2249
+# enable=add-default-case
+
+# https://github.com/koalaman/shellcheck/wiki/SC2244
+enable=avoid-nullary-conditions
+
+# https://github.com/koalaman/shellcheck/wiki/SC2312
+# enable=check-extra-masked-returns
+
+# https://github.com/koalaman/shellcheck/wiki/SC2310
+# https://github.com/koalaman/shellcheck/wiki/SC2311
+# enable=check-set-e-suppressed
+
+# enable=check-unassigned-uppercase
+
+# https://github.com/koalaman/shellcheck/wiki/SC2230
+enable=deprecate-which
+
+# https://github.com/koalaman/shellcheck/wiki/SC2248
+enable=quote-safe-variables
+
+# https://github.com/koalaman/shellcheck/wiki/SC2292
 # https://google.github.io/styleguide/shellguide.html#s6.3-tests
 enable=require-double-brackets
 
-# https://www.shellcheck.net/wiki/SC2250
+# https://github.com/koalaman/shellcheck/wiki/SC2250
 # https://google.github.io/styleguide/shellguide.html#s5.6-variable-expansion
 enable=require-variable-braces