Improve readme formatting and explanations

Updated explanations in the readme for clarity and formatting.

Author: javadev

src/main/java/g0001_0100/s0008_string_to_integer_atoi/readme.md

@@ -21,7 +21,13 @@ Return the integer as the final result.
 
 **Explanation:**
 
-The underlined characters are what is read in and the caret is the current reader position. Step 1: "42" (no characters read because there is no leading whitespace) ^ Step 2: "42" (no characters read because there is neither a '-' nor '+') ^ Step 3: "<ins>42</ins>" ("42" is read in) ^ 
+    The underlined characters are what is read in and the caret is the current reader position.
+    Step 1: "42" (no characters read because there is no leading whitespace)
+             ^
+    Step 2: "42" (no characters read because there is neither a '-' nor '+')
+             ^
+    Step 3: "42" ("42" is read in)
+              ^ 
 
 **Example 2:**
 
@@ -31,7 +37,12 @@ The underlined characters are what is read in and the caret is the current reade
 
 **Explanation:**
 
-Step 1: " \-042" (leading whitespace is read and ignored) ^ Step 2: " <ins>\-</ins>042" ('-' is read, so the result should be negative) ^ Step 3: " -<ins>042</ins>" ("042" is read in, leading zeros ignored in the result) ^ 
+    Step 1: "___-042" (leading whitespace is read and ignored)
+                ^
+    Step 2: " -042" ('-' is read, so the result should be negative)
+              ^
+    Step 3: " -042" ("042" is read in, leading zeros ignored in the result)
+                 ^ 
 
 **Example 3:**
 
@@ -41,7 +52,12 @@ Step 1: " \-042" (leading whitespace is read and ignored) ^ Step 2: " <ins>\-</i
 
 **Explanation:**
 
-Step 1: "1337c0d3" (no characters read because there is no leading whitespace) ^ Step 2: "1337c0d3" (no characters read because there is neither a '-' nor '+') ^ Step 3: "<ins>1337</ins>c0d3" ("1337" is read in; reading stops because the next character is a non-digit) ^ 
+    Step 1: "1337c0d3" (no characters read because there is no leading whitespace)
+             ^
+    Step 2: "1337c0d3" (no characters read because there is neither a '-' nor '+')
+             ^
+    Step 3: "1337c0d3" ("1337" is read in; reading stops because the next character is a non-digit)
+                 ^ 
 
 **Example 4:**
 
@@ -51,7 +67,12 @@ Step 1: "1337c0d3" (no characters read because there is no leading whitespace) ^
 
 **Explanation:**
 
-Step 1: "0-1" (no characters read because there is no leading whitespace) ^ Step 2: "0-1" (no characters read because there is neither a '-' nor '+') ^ Step 3: "<ins>0</ins>\-1" ("0" is read in; reading stops because the next character is a non-digit) ^ 
+    Step 1: "0-1" (no characters read because there is no leading whitespace)
+             ^
+    Step 2: "0-1" (no characters read because there is neither a '-' nor '+')
+             ^
+    Step 3: "0-1" ("0" is read in; reading stops because the next character is a non-digit)
+              ^ 
 
 **Example 5:**
 
@@ -66,4 +87,4 @@ Reading stops at the first non-digit character 'w'.
 **Constraints:**
 
 *   `0 <= s.length <= 200`
-*   `s` consists of English letters (lower-case and upper-case), digits (`0-9`), `' '`, `'+'`, `'-'`, and `'.'`.
+*   `s` consists of English letters (lower-case and upper-case), digits (`0-9`), `' '`, `'+'`, `'-'`, and `'.'`.