chore(doc): spelling (#3172)

* Spelling: 'an unicode' -> 'a unicode'

* fix(changelog) spelling

* Remove double spaces

* Spelling

src/draw/lv_draw_mask.c

@@ -202,7 +202,7 @@ void * lv_draw_mask_remove_custom(void * custom_id)
 
 /**
  * Free the data from the parameter.
- * It's called inside  `lv_draw_mask_remove_id` and `lv_draw_mask_remove_custom`
+ * It's called inside `lv_draw_mask_remove_id` and `lv_draw_mask_remove_custom`
  * Needs to be called only in special cases when the mask is not added by `lv_draw_mask_add`
  * and not removed by `lv_draw_mask_remove_id` or `lv_draw_mask_remove_custom`
  * @param p pointer to a mask parameter

src/draw/lv_draw_mask.h

@@ -280,7 +280,7 @@ void * lv_draw_mask_remove_custom(void * custom_id);
 
 /**
  * Free the data from the parameter.
- * It's called inside  `lv_draw_mask_remove_id` and `lv_draw_mask_remove_custom`
+ * It's called inside `lv_draw_mask_remove_id` and `lv_draw_mask_remove_custom`
  * Needs to be called only in special cases when the mask is not added by `lv_draw_mask_add`
  * and not removed by `lv_draw_mask_remove_id` or `lv_draw_mask_remove_custom`
  * @param p pointer to a mask parameter

src/draw/lv_img_decoder.c

@@ -146,7 +146,7 @@ lv_res_t lv_img_decoder_open(lv_img_decoder_dsc_t * dsc, const void * src, lv_co
         dsc->decoder = decoder;
         res = decoder->open_cb(decoder, dsc);
 
-        /*Opened successfully. It is a good decoder to for this image source*/
+        /*Opened successfully. It is a good decoder for this image source*/
         if(res == LV_RES_OK) return res;
 
         /*Prepare for the next loop*/

src/draw/lv_img_decoder.h

@@ -154,8 +154,8 @@ lv_res_t lv_img_decoder_get_info(const void * src, lv_img_header_t * header);
 
 /**
  * Open an image.
- * Try the created image decoder one by one. Once one is able to open the image that decoder is save in `dsc`
- * @param dsc describe a decoding session. Simply a pointer to an `lv_img_decoder_dsc_t` variable.
+ * Try the created image decoders one by one. Once one is able to open the image that decoder is saved in `dsc`
+ * @param dsc describes a decoding session. Simply a pointer to an `lv_img_decoder_dsc_t` variable.
  * @param src the image source. Can be
  *  1) File name: E.g. "S:folder/img1.png" (The drivers needs to registered via `lv_fs_add_drv()`)
  *  2) Variable: Pointer to an `lv_img_dsc_t` variable