docs: update README.md

0x0B-malloc_free/README.md

@@ -24,3 +24,54 @@ All of the following files are programs written in C:
 | [5-argstostr.c](./5-argstostr.c) | Concatenates all the arguments of a program |
 | [100-strtow.c](./100-strtow.c) | Splits a string into words |
 
+## Tasks :page_with_curl:
+
+* **0. Float like a butterfly, sting like a bee**
+  * [0-create_array.c](./0-create_array.c): C function that returns a pointer to a
+  newly-allocated space in memory containing an array of characters.
+    * The array of characters is initialized to the parameter `c`.
+    * If the function fails or receives `size` equal to `0` - returns `NULL`.
+
+* **1. The woman who has no imagination has no wings**
+  * [1-strdup.c](./1-strdup.c): C function that returns a pointer to a newly-allocated space
+  in memory containing a copy of the string passed as parameter.
+    * Returns a pointer to a new string which is a duplicate of the string `str`.
+    * Memory for the new string is obtained with `malloc` and can be freed with `free`.
+    * If `str` is `NULL` or insufficient memory was available - returns `NULL`.
+
+* **2. He who is not courageous enough to take risks will accomplish nothing in life**
+  * [2-str_concat.c](./2-str_concat.c): C function that returns a pointer to a
+  newly-allocated space in memory containing the concatenation of two strings passed as
+  parameters.
+    * The returned pointer contains the contents of `s1` followed by `s2` and is
+    null-terminated.
+    * The function treats `NULL` as an empty string.
+    * If the function fails - returns `NULL`.
+
+* **3. If you even dream of beating me you'd better wake up and apologize**
+  * [3-alloc_grid.c](./3-alloc_grid.c): C function that returns a
+  pointer to a newly-allocated space in memory containing a two-dimensional array of integers.
+    * Each element of the two-dimensional array is initialized to `0`.
+    * If the function fails or either of `width` or `height` is
+    `0` or negative - returns `NULL`.
+
+* **4. It's not bragging if you can back it up**
+  * [4-free_grid.c](./4-free_grid.c): C function that frees a two-dimensional array previsouly
+  created by the `alloc_grid` function defined in `3-alloc_grid.c`.
+    * The program does not crash upon receiving invalid two-dimensional arrays.
+
+* **5. It isn't the mountains ahead to climb that wear you out; it's the pebble in your shoe**
+  * [5-argstostr.c](./5-argstostr.c): C function that returns a pointer to a
+  newly-allocated space in memory containing the concatenation of all the arguments of the
+  program.
+    * Each argument is followed by a `\n` in the new string.
+    * If `ac == 0`, `av == NULL`, or the function fails - returns `NULL`.
+
+* **6. I will show you how great I am**
+  * [100-strtow.c](./100-strtow.c): C function that splits a string into words.
+    * Returns a pointer to a newly-allocated space in memory containing
+    an array of strings (words).
+    * Each element of the array of strings contains a single word, null-terminated.
+    * The last element of the returned array is `NULL`.
+    * Words are separated by spaces.
+    * If `str == NULL`, `str == ""`, or the function fails - returns `NULL`.