Rollup merge of #25408 - Nashenas88:rust-book-stack-and-heap-typo, r=steveklabnik

I fixed the typo of the value of e in the memory tables. It is a reference to d, and so it should contain the memory location of d. I also fixed the incorrectly formatted tables so they display properly in html pages.

Author: steveklabnik

src/doc/trpl/the-stack-and-the-heap.md

@@ -430,7 +430,7 @@ Next, `foo()` calls `bar()` with `x` and `z`:
 |  2<sup>30</sup>      |      | 20                   |
 | (2<sup>30</sup>) - 1 |      | 5                    |
 | ...                  | ...  | ...                  |
-| 10                   | e    | 4                    |
+| 10                   | e    | 9                    |
 | 9                    | d    | (2<sup>30</sup>) - 1 |
 | 8                    | c    | 5                    |
 | 7                    | b    | 4                    |
@@ -455,7 +455,7 @@ At the end of `bar()`, it calls `baz()`:
 | ...                  | ...  | ...                  |
 | 12                   | g    | 100                  |
 | 11                   | f    | 4                    |
-| 10                   | e    | 4                    |
+| 10                   | e    | 9                    |
 | 9                    | d    | (2<sup>30</sup>) - 1 |
 | 8                    | c    | 5                    |
 | 7                    | b    | 4                    |
@@ -477,7 +477,7 @@ After `baz()` is over, we get rid of `f` and `g`:
 |  2<sup>30</sup>      |      | 20                   |
 | (2<sup>30</sup>) - 1 |      | 5                    |
 | ...                  | ...  | ...                  |
-| 10                   | e    | 4                    |
+| 10                   | e    | 9                    |
 | 9                    | d    | (2<sup>30</sup>) - 1 |
 | 8                    | c    | 5                    |
 | 7                    | b    | 4                    |