refactor(程序): 更新事件监听和多行字符串格式

将imageview.lua中的event.pull改为os.pullEvent
在time.lua中使用多行字符串语法改善帮助文本格式

data/computercraft/lua/rom/programs/imageview.lua

@@ -2,7 +2,7 @@
 local http = require("http")
 local paintutils = require("paintutils")
 local term = require("term")
-local event = require("event")
+
 local shell = require("shell")
 
 -- 帮助信息函数
@@ -78,7 +78,7 @@ local function main(args)
 
   -- 监听ESC键
   while true do
-    local _, key = event.pull("key")
+    local _, key = os.pullEvent("key")
     if key == 27 then -- ESC键
       term.clear()
       term.setCursorPos(1, 1)

data/computercraft/lua/rom/programs/time.lua

@@ -7,14 +7,15 @@ local function printHelp()
   print("Options:")
   print("  --help, -h       Show this help message")
   print("  --format, -f <fmt>  Specify time format string (see below for details)")
-  print("
-Formats for --format option:")
-  print("  %Y: Year (4 digits)")
-  print("  %m: Month (01-12)")
-  print("  %d: Day (01-31)")
-  print("  %H: Hour (00-23)")
-  print("  %M: Minute (00-59)")
-  print("  %S: Second (00-59)")
+  print([[
+Formats for --format option:
+  %Y: Year (4 digits)
+  %m: Month (01-12)
+  %d: Day (01-31)
+  %H: Hour (00-23)
+  %M: Minute (00-59)
+  %S: Second (00-59)
+]])
   print("  %A: Full weekday name")
   print("  %B: Full month name")
   print("